Practice Test

Q1) Which of the cells is easily damaged by the short circuiting ? Show Answer

Q2) The current capacity of a secondary cell is independent of :
Show Answer

Q3) E.M.F. of cell depends upon: Show Answer

Q4) Cells are joined in parallel to get maximum current when: Show Answer

Q5) Cells are joined in series to get maximum current when : Show Answer

Q6) Side-wire bridge is an application of : Show Answer

Q7) Two batteries of different e.m.f. and internal resistance are connected in series with an external resistor and current in circuit is 3 A. When polarity of one is reversed the current is 1 A. The ratio of their e.m.f.'s is : Show Answer

Q8) A piece of a wire is cut into four equal parts and the pieces are bundled together closely to form a thicker wire. Compared with that of the original, the resistance of thicker wire is : Show Answer

Q9) A wire stretched to increase its length by 10 %. What is the percentage increase in resistance ? Show Answer

Q10) External resistance of a circuit is R which is connected to n exactly similar cells. If the current in the circuit is the same whether the cells are in series or in parallel, the value of internal resistance of each cell is : Show Answer

Q11) 12 cells each having same e.m.f. are connected in series and are kept in a closed box. Some of them are wrongly connected. Two identical cells are connected in series to aid this battery and the current is 3 A when circuit is completed through an external resistance. The current is 2 A if the cells are made to oppose the battery through same resistance. The number of cells wrongly connected are: Show Answer

Q12) Kirchhoff's second law is based on the law of conservation of : Show Answer

Q13) For uniform wires with following dimensions, the resistance is least for: Show Answer

Q14) The terminal potential difference of a battery exceeds its e.m.f. when it is connected : Show Answer

Q15) The conductivity of super-conductor is : Show Answer

Q16) The resistance of a discharge tube is : Show Answer

Q17) A man wants to test his ammeter whose range is 0-1 ampere. He connects it to a 12 V storage battery and a carbon resistance of 48 ohm 0.5 watt. Which of the following is most likely to happen ? Show Answer

Q18) A moving coil voltmeter is being used for measuring P.D. across a resistor of resistance r in which a current I is flowing. The voltmeter has a resistance R. The voltmeter will measure the P.D. more correctly as : Show Answer

Q19) An electric current of 5 A is divided into three branches forming parallel combination. The length of wire in the three branches are in the ratio 2:3:4 while their diameters are in the ratio 3:4:5. Find the current in each branch if wires are of the same material. Show Answer

Q20) 36 cells each of internal resistance 0.5 W and e.m.f. 1.5 V each are used to send current through an external circuit of 2 W resistance. Find the best mode of grouping them and current through external circuit. Show Answer

Q21) n identical cells, each e.m.f. E and internal resistance r, are joined in series to form a closed circuit. The potential difference across any one of the cell is : Show Answer

Q22) The current in a copper wire is increased by increasing the potential difference between its ends. Which of the following statements regarding n, the number of charge carries per unit volume in the wire and v, the drift velocity of the charge carries is correct ? Show Answer

Q23) A piece of a wire is cut into four parts and the pieces are bundled together side by side to form a thick wire. Compared with that of the original wire, the resistance of the bundle is : Show Answer

Q24) N identical cells, each e.m.f. E and internal resistance r, are joined in series to form 'a' closed circuit. One cell A is joined with the reverse polarity. The potential difference across each cell except A is : Show Answer

Q25) The masses of three wires of copper are in the ratio 1:3:5 and their lengths are in ratio 5:3:1. The ratio of their electrical resistances is : Show Answer

Q26) The momentum acquired by the electrons in length l of wire a current I starts to flow is : Show Answer

Q27) A current I flows in a wire of circular cross-section with the free electrons traveling with a drift velocity v. The drift velocity of electrons when a current 2 I flows in another wire of twice the radius and of the same material is : Show Answer

Q28) One meter long metallic wire is broken into two unequal parts P and Q. The part P is uniformly extended into another wire R. Length of R is twice the length of P and the resistance of R is equal to that of Q. The ratio of the resistances of P and R is : Show Answer

Q29) Two voltmeters P and Q give the same reading when connected across a resistor X in a current - carrying circuit. But when connected across another resistor Y, the reading comes much lower in P than in Q. If P, Q, X, Y represent the respective resistance, the data shows that : Show Answer

Q30) Two conductors, made of the same material, have lengths L and 2L, but have equal resistances. The two are connected in series in a circuit in which current is flowing. Which of the following is/are correct ? Show Answer

Q31) If an electric current is passed through nerves the man : Show Answer

Q32) n identical cells are joined in series with two cells A and B with reversed polarities e.m.f. of each cell is E and internal resistance is r. Potential difference across cell A or B is (n > 4): Show Answer

Q33) An ammeter with internal resistance 90 ohm reads 1.85 A when connected in a circuit containing a battery and two resistances of 700 ohm and 410 ohm in series. Actual current will be : Show Answer

Q34) Is it possible that any battery has some constant value of e.m.f. but the potential difference between the plates is zero ? Show Answer

Q35) The infinity resistance plug in post-office box has Show Answer

Q36) If a copper wire is stretched to make it 0.1% longer, then the percentage change in resistance is approximately : Show Answer

Q37) When a resistance of 2 ohm is connected across the terminals of a cell, the current is 0.5 A. When the resistance is increased to 5 ohm, the current is 0.25 A. The e.m.f. of the cell is : Show Answer

Q38) For a metallic wire, the ratio V/I ( V = applied potential difference, I = current flowing ) : Show Answer

Q39) Given a current carrying wire of non-uniform cross-section. Which of the following is constant throughout the length of the wire ? Show Answer

Q40) Dimensions of electric current is : Show Answer

Q41) When a lamp is connected in series with a capacitor, then the lamp will : Show Answer

Q42) The internal resistance of a cell is the resistance of : Show Answer

Q43) Two cells when connected in series are balanced on 8 cm on a potentiometer. IF the cells are connected with polarities of one of the cell is reversed, they balance of 2 m. The ratio of e.m.f.'s of the two cells is : Show Answer

Q44) A steady current flows in a metallic conductor of non-uniform cross-section. Which of the following quantity is constant along the conductor ? Show Answer

Q45) Potential difference across the terminals of a battery is 50 V, when 11 A current is drawn. And it is 60 V, 1 A current is drawn. The e.m.f. and internal resistance of battery is : Show Answer

Q46) The drift velocity does not depend upon : Show Answer

Q47) If the radius of the copper wire carrying a current is doubled, the drift velocity of the electrons will : Show Answer

Q48) The electrical conductivity of metal decreases with temperature because : Show Answer

Q49) A number of 100 volt lamps connected in parallel are fed by a 130 V battery having an internal resistance of 2.6 ohm. If the resistance of each lamp is 200 ohm and the resistance of conducting wires is 0.40 ohm, the number of lamps which the battery can light properly is : Show Answer

Q50) A battery of e.m.f. 10 V and internal resistance 0.5 ohm is connected across a variable resistance R. The value of R for which the power delivered in it is maximum is given by : Show Answer

Q51) To convert a galvanometer into voltmeter we must connect a : Show Answer

Q52) The resistance of a conductor increases with : Show Answer

Q53) When a wire of resistance R is stretched and its radius becomes r/2, then new resistance will be : Show Answer

Q54) Kirchhoff's first law is based on the law of conversation of : Show Answer

Q55) A wire resistance R is stretched till its radius is half of the original value. Then the resistance of the stretched wire is : Show Answer

Q56) The drift velocity of free electrons in a conductor is v when a current i is flowing in it. If both the radius and current are doubled, then drift velocity will be : Show Answer

Q57) Which of the following has the largest resistance ? Show Answer

Q58) The resistivity of metal increases with increase in temperature because : Show Answer

Q59) A cell of e.m.f. has a resistance R connected across it, and a voltmeter measures the potential difference across the terminals of the cell as V. The internal resistance of the cell is : Show Answer

Q60) Ohm's law is not obeyed by : Show Answer

Q61) Express which of the following set up can be used to verify Ohm's law ? Show Answer

Q62) In a Wheatstone's bridge, all the four arms have equal resistance R. IF the resistance of the galvanometer arm is also R, the equivalent resistance of the combination as seen by the battery is : Show Answer

Q63) A cell e.m.f. E is connected across a resistance r. The potential difference between the terminals of the cell is found to be V. The internal resistance of the cell must be : Show Answer

Q64) n cells of each e.m.f. E and internal resistance r send the same current through an external resistance R whether the cells are connected in series or in parallel. Then : Show Answer

Q65) Two wires of the same material and the same length are connected to the two gaps of a meter bridge. The balancing length measured from left is 25 cm. The ratio of radius of the wire in the left gap to that in the right gap is : Show Answer

Q66) When a current is divided between two resistors according to Kirchhoff's law, then the heat produced is : Show Answer

Q67) The electric resistance of a certain wire of iron is R. If its length and radius both doubled, then its Show Answer

Q68) Resistance n each of r ohm, when connected in parallel combination, give an equivalent resistance of R. If these resistances are connected in series, then the new combination would have a resistance equal to : Show Answer

Q69) Current provided by a battery is maximum when : Show Answer

Q70) Which of the following has negative temperature coefficient of resistance ? Show Answer

Q71) For measuring the voltage of any circuit, the potentiometer is preferred to the voltmeter because : Show Answer

Q72) In order to pass 10 % of main current through a moving coil galvanometer of 99 ohm, the resistance of the required shunt is : Show Answer

Q73) A cell of negligible resistance and e.m.f. 2 volt is connected to series combination of 2, 3 and 5 ohm. The P.D. in volt between the terminals of 3 ohm resistance will be : Show Answer

Q74) A wire is wound in the form of a solenoid or length l and diameter d. When a strong current is passed through the solenoid, there is tendency to : Show Answer

Q75) The length of the wire is doubled. Its conductance will be : Show Answer

Q76) When a wire of uniform cross-section a, length l and resistance R is bent into complete circle, resistance between any two diametrically opposite points will be : Show Answer

Q77) The dimensions of electrical resistance are: Show Answer

Q78) To draw maximum current from a combination of cells, how should the cells be grouped ? Show Answer

Q79) A wire is cut into 4 pieces, which are put together by sides so obtain one conductor. If the original resistance of wire was R, the resistance of the bundle will be : Show Answer

Q80) Ohm's law is true : Show Answer

Q81) A voltmeter has a resistance of G ohm and range V volt. The value of resistance used in series to convert it into a voltmeter of range nV volt is : Show Answer

Q82) Two bulbs of equal wattage, one having carbon filament and the other having a tungsten filament are connected in series to the mains, then : Show Answer

Q83) Dimensions of resistance in an electrical circuit, in terms of dimensions of mass M, of length L, of time T and of current I, would be : Show Answer

Q84) A galvanometer acting as a voltmeter will have : Show Answer

Q85) A wire with a certain material is stretched slowly by ten per cent. Its new resistance and specific resistance becomes respectively : Show Answer

Q86) A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 m A current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be : Show Answer

Q87) Consider following statements :
(1) Kirchhoff's junction law follows from the conservation of charge.
(2) Kirchoff's loop law from the conservation of energy.
Which of the following is correct ? Show Answer

Q88) Two wires A and B are made of copper. Both wires are 1 meter long but wire A is 1 mm thick and wire B is 2 mm thick. The specific resistance is : Show Answer

Q89) When a potential difference V is applied across a conductor at temperature T, the drift velocity of electron is proportional to : Show Answer

Q90) When a potential difference V is applied across a conductor at temperature T, the thermal speed of electron is proportional to : Show Answer

Q91) The non ohmic device which exhibits a region of negative resistance is : Show Answer

Q92) An electric bulb has a rating of 500 W, 100 V. It is used a circuit having a 200 V supply. What resistance must be connected in series with the bulb so that it delivers 500 W ? Show Answer

Q93) For accurate measurements, the resistance of a voltmeter should be Show Answer

Q94) The resistance of a straight conductor does not depend on its Show Answer

Q95) In a potentiometer arrangement, a cell 1.25 V gives a balance point at 35 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63 cm the emf of the second cell is Show Answer

Q96) Given n resistors, combine them to get maximum and minimum resistance. The ratio of maximum to minimum resistance is Show Answer

Q97) If the combination is connected to a 20 V battery, then current drawn from the battery is Show Answer

Q98) A copper wire is stretched to make it 0.1% longer. The percentage increase in resistance will be Show Answer

Q99) How many electrons per second constitute a current of one micro ampere? Show Answer

Q100) A piece of copper and a piece of germanium are cooled from the room temperature down to 77 K. Show Answer

Q101) The capacity of a storage cell is 5 ampere hour. The maximum current it can supply for one hour is Show Answer

Q102) An electric cell does 5 joule of work in carrying 10 C of charge around a closed electric circuit. The electromotive force of the cell is Show Answer

Q103) A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/quantities constant along the length of the conductor is/are Show Answer

Q104) Potential difference of a cell in an open circuit is 6 volt but it falls to 4 volt when a current of 2 A is drawn from it. The internal resistance of the cell is Show Answer

Q105) We are able to obtain fairly large currents in a conductor because Show Answer

Q106) A piece of wire is cut into four equal parts and the piece are bundled together side by side to form a thick wire. Compared with that of the original wire, the resistance of the bundle is Show Answer

Q107) Statement 1 : Potential difference V is applied across a copper wire of diameter d and length L. When the diameter of the wire is doubled keeping the other parameters same, the drift speed of the electrons remains unchanged.
Statement 2 : Current density remains the same here. Show Answer

Q108) Statement 1 : An electrical bulb starts glowing instantly as it is switched on.
Statement 2 : Drift speed of electrons in a metallic wire is very large for metallic conductors. Show Answer

Q109) A wire is carrying 2 A current from left to right. Drift speed of electron in conductors is 1 mm/s. A person is moving towards right with 1 mm/s velocity parallel to conductor. Average velocity of electron with respect to this person. Show Answer

Q110) Current through above conductor with respect to moving person Show Answer

Q111) A galvanometer of resistance 98 ohms is shunted by a resistance of 2 ohms. The fraction of the total current that pass through is Show Answer

Q112) The potential difference between the terminals of a cell is open circuit is 2.2 volt. With resistance of 5 ohm across the terminals of a cell, the terminal potential difference is 1.8 volt. The internal resistance of the cell is Show Answer

Q113) Copper and germanium are both cooled to 70 K from room temperature, then Show Answer

Q114) A Daniel cell is balanced on 125 cm length of a potentiometer wire. Now the cell is short-circuited by a resistance of 2 ohm and the balance is obtained at 100 cm. The internal resistance of the Daniel cell is Show Answer

Q115) Consider four circuits shown in the figure below. In which circuit power dissipated is greatest? (Neglect the internal resistance of the power supply) Show Answer

Q116) Statement 1 : 10 identical bulbs are connected in series. If one of the bulb gets fused and the remaining 9 bulbs are reconnected across the same supply in series then, light gets increased in the room.
Statement 2 : The power consumption by 9 bulbs is more than the 10 bulbs. Show Answer

Q117) Statement 1 : Current is passed through a metallic wire, heating it red. When cold water is poured on half of its portion then rest of the half portion becomes more hot.
Statement 2 : Resistance decreases due to decreases in temperature and so current through wire increases. Show Answer

Q118) What is the emf of cell used in experiment? Show Answer

Q119) What is the maximum current that can be withdraw from cell? Show Answer

Q120) What is the maximum power can be with draw from cell? Show Answer

Q121) If an increase in length of copper wire is 0.5% due to stretching, the percentage increase in its resistance will be Show Answer

Q122) A battery of emf E and internal resistance r is connected to an external resistance R the condition for maximum power transfer is Show Answer

Q123) A resistor has a colour code of green, blue, brown and silver. What is its resistance? Show Answer

Q124) A battery having e.m.f. 5V and internal resistance 0.5 Ω is connected with a resistance of 4.5 Ω then the voltage at the terminals of battery is Show Answer

Q125) The length of a conductor is doubled and its radius is halved, its specific resistance is Show Answer

Q126) In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be Show Answer

Q127) The chemical equivalent of silver is 108. If the current in a silver voltmeter is 2 amp, the time required to deposit 27 grams of silver will be Show Answer

Q128) Which of the following set up can be used to verify the Ohm’s law? Show Answer

Q129) Two wires of the same material and equal length are joined in parallel combination. If one of them has half the thickness of the other and the thinner wire has a resistance of 8 ohms, the resistance of the combination is equal to Show Answer

Q130) If the temperature of cold junction of thermocouple is lowered, then the neutral temperature Show Answer

Q131) Which of the following statements is correct? Show Answer

Q132) Two electric bulbs, one of 200 volt 40 watt and the other 200 volt 100 watt are connected in a house wiring circuit Show Answer

Q133) An electric current passes through a circuit containing two wires of the same material connected in parallel. If the lengths of the wires are in the ratio of 4/3 and radius of the wires are in the ratio of 2/3, then the ratio of the current passing through the wires will be Show Answer

Q134) A 100 watt bulb working on 200 volt and a 200 watt bulb working on 100 volt have Show Answer

Q135) With the rise of temperature the resistivity of a semiconductor Show Answer

Q136) A battery consists of a variable number 'n' of identical cells having internal resistances connected in series. The terminals of battery are short circuited and the current i is measured. Which of the graph below slows the relationship between i and n? Show Answer

Q137) Which of the following circuits is correct for verification of Ohm’s law? Show Answer

Q138) If 2.2 kilowatt power is transmitted through a 10 ohm line at 22000 volt, the power loss in the form of heat will be Show Answer

Q139) Masses of the three wires of same material are in the ratio of 1:2:3 and their lengths in the ratio of 3:2:1. Electrical resistance of these wires will be in the ratio of Show Answer

Q140) A galvanometer can be converted into a voltmeter by connecting Show Answer

Q141) Two conductors of the same material have their diameters in the ratio 1 : 2 and their lengths in the ratio 2 : 1. If the temperature difference between their ends is the same, then the ratio of amounts of heat conducted per second through them will be Show Answer

Q142) A railway compartment is lit up by thirteen lamps each taking 2.1 A at 15 V. The heat generated per second in each lamp will be Show Answer

Q143) Potential gradient is defined as Show Answer

Q144) By using only two resistances coils-singly, in series or in parallel one should be able to obtain resistance of 3,4,12 and 16 ohm. The separate resistance of the coil are Show Answer

Q145) There are two electric bulbs of 40 W and 100 W. Which one will be brighter when first connected in series and then in parallel Show Answer

Q146) The reciprocal of resistance is Show Answer

Q147) The accurate measurement of emf can be obtained using Show Answer

Q148) A current of 2 A passing through conductor produces 80 J of heat in 10 seconds. The resistance of the conductor is Show Answer

Q149) In a copper voltmeter , if the current (I) and time (t) variations of the type as shown in figure, the mass deposited in 30 min is [Atomic weight of copper is 63.5 and Faraday constant is 96500 C per g equivalent] Show Answer

Q150) The graph between resistivity and temperature, for a limited range of temperatures, is a straight line for a material like Show Answer

Q151) A house wife uses a 100 W bulb 8 h a day , and an electric heater of 300 W for 4 h a day. The total cost for the month of June at the rate of 0.05 rupee per unit will be Show Answer

Q152) Two cells, each of e.m.f.E and internal resistance r are connected in parallel between the resistance R. The maximum energy given to the resistor will be, only when Show Answer

Q153) An electric bulb is rated 60 W, 220 V. The resistance of its filament is Show Answer

Q154) The tolerance level of a resistor with the colour code red, blue, orange, gold is Show Answer

Q155) For a given thermocouple neutral temperature Show Answer

Q156) A battery consists of a variable number (n) of identical cells, each having an internal resistance r connected in series. The terminal of the battery is short-circuited. A graph of current versus the number of cells will be as shown in figure Show Answer

Q157) In a potentiometer of one metre length, an unknown e.m.f. voltage source is balanced at 60 cm length of potentiometer wire, while a 3 volt battery is balanced at 45 cm length. Then the e.m.f. of the unknown voltage source is Show Answer

Q158) x g of Ag is deposited by passing 4 A of current of for 1 h. How many gram of Ag will be deposited by passing 6 A for 40 min? Show Answer

Q159) Two bulbs 40 W and 60 W and rated voltage 240 V are connected in series across a potential difference of 420 V. Which bulb will work at above its rated voltages? Show Answer

Q160) Two heater wires of equal length are first connected in series and then in parallel. The ratio of heat produced in the two cases is Show Answer

Q161) When a piece of aluminium wire of finite length is drawn through a series of dies to reduce its diameter to half its original value, its resistance will become Show Answer

Q162) Watt-hour meter measures Show Answer

Q163) A potentiometer having the potential gradient of 2 mV/cm is used to measure the difference of potential across a resistance of 10 ohm. If a length of 50 cm of the potentiometer wire is required to get the null point, the current passing through the 10 ohm resistor is (in mA) Show Answer

Q164) Two electric lamps of 40 watt each are connected in parallel. The power consumed by the combination will be Show Answer

Q165) Which arrangement of four identical resistance should be used to draw maximum energy from a cell of voltage V? Show Answer

Q166) An electric fan and a heater are marked as 100 watt, 220 volt and 1000watt, 220 volt respectively. The resistance of the heater is Show Answer

Q167) 5 ampere of current is passed through a metallic conductor. The charge flowing in one minute in coulomb will be Show Answer

Q168) The length of the wire is doubled. Its conductance will be Show Answer

Q169) A student has 10 resistors of resistance 'r'. The minimum resistance made by him from given resistors is Show Answer

Q170) Which of the following relation is wrong? Show Answer

Q171) An ammeter reads 0.90 A when connected in series with a silver voltmeter that deposits 2.60 g of silver in 40 min. By what percentage is the ammeter reading is correct? Atomic weight of silver = 108 and 1 F = 96500 C? Show Answer

Q172) The following four wires are made of the same material and are at the same temperature. Which one of them has the highest electrical resistance? Show Answer

Q173) Two different metals are joined end to end. One end is kept at constant temperature and the other end is heated to a very high temperature. The high depicting the thermo e.m.f. is Show Answer

Q174) Which statement is true?
(i) Kirchoff’s law is equally applicable to both AC and DC.
(ii) Semiconductors have a positive temperature coefficient of resistance.
(iii) Meter bridge is greater sensitive when the resistance of all four arms of the bridge is of the same order.
(iv) The emf of a cell depends upon the size and area of electrodes. Show Answer

Q175) An electric iron draws 5 amp a TV set draws 3 amp and refrigerator graws 2 amp from a 220 volt main line. The three appliances are connected in parallel. If all the three are operating at the same time, the fuse used may be of Show Answer

Q176) There are three resistance coils of equal resistance. The maximum number of resistances you can obtain by connecting them in any manner you choose, being free to use any number of the coils in any way is Show Answer

Q177) To get the maximum current from a parallel combination of n identical cells each of internal resistance r and external resistance R, when Show Answer

Q178) The resistance of a discharge tube is Show Answer

Q179) In an electroplating experiment, m gm of silver is deposited when 4 ampere of current flows for 2 minute. The amount (in gm) of silver deposited by 6 ampere of current for 40 second will be Show Answer

Q180) For which of the following the resistance decreases on increasing the temperature Show Answer

Q181) Current flows through a metabolic conductor whose area of cross-section increases in the direction of the current. If we move in this direction, Show Answer

Q182) The resistance of a metal increases with increasing temperature because Show Answer

Q183) By mistake a voltmeter is connected in series and an ammeter is connected in parallel with a resistance in an electrical circuit. What will happen to the instrument? Show Answer

Q184) The electric intensity E, current density j and specific resistance k are related to each other by the relation Show Answer

Q185) The same mass of copper is drawn into two wires 1 mm and 2 mm thick. Two wires are connected in series and current is passed through them. Heat produced in the wire is in the ratio Show Answer

Q186) Resistance in the two gaps of a meter bridge are 10 ohm and 30 ohm respectively. If the resistances are interchanged the balance point shifts by Show Answer

Q187) An electric bulb rated 220 V, 100 W is connected in series with another bulb rated 220 V, 60 W. If the voltage across the combination is 220 V, the power consumed by the 100 W bulb will be about Show Answer

Q188) It is easier to start a car engine on a hot day than on a cold day. This is because the internal resistance of the car battery Show Answer

Q189) An electric lamp is marked 60 W,230 V. The cost of a 1 kWh of energy is Rs.1.25. The cost of using this lamp 8 hrs a day for 30 days is Show Answer

Q190) Two resistances R and 2R are connected in parallel in an electric circuit. The thermal energy developed in R and 2R are in the ratio Show Answer

Q191) An electric bulb is rated 220 V – 100 W. The power consumed by it when operated on 110 V will be Show Answer

Q192) Two wires of the same material but of different diameters carry the same current i. If ratio of their diameters is 1:2, then the corresponding ratio of their mean drift velocities will be Show Answer

Q193) The net resistance of a voltmeter should be large to ensure that Show Answer

Q194) The maximum current that flows through a fuse wire before it blows out varies with its radius as Show Answer

Q195) Four wires AB, BC, CD, DA of resistance 4 ohm each and a fifth wire BD of resistance 8ohm are joined to form a rectangle ABCD of which BD is a diagonal. The effective resistance between the points A and B is Show Answer

Q196) To deposit one litre of hydrogen at 22.4 atmosphere from acidulated water, the quantity of electricity that must pass through is Show Answer

Q197) A 25 W, 220 V bulb and a 100 W, 220 V bulb are connected in parallel across a 440 V line Show Answer

Q198) An electric bulb of 100 watt is connected to a supply of electricity of 220 V. Resistance of the filament is Show Answer

Q199) Which of the following is not a correct statement? Show Answer

Q200) According to Faraday’s law of electrolysis, the amount of decomposition is proportional to Show Answer

Q201) A 100 ohm galvanometer gives full scale deflection at 10 mA. How much shunt is required to read 100 mA? Show Answer

Q202) The steady current flows in a metallic conductor of non-uniform cross-section. The quantity/quantities constant along the length of the conductor is/are Show Answer

Q203) There are 8 equal resistance R. Two are connected in parallel, such four groups are connected in series, the total resistance of the system will be Show Answer

Q204) Two electric bulbs whose resistances are in the ratio of 1∶2 are connected in parallel to a constant voltage source. The powers dissipated in them have the ratio Show Answer

Q205) Some electric bulbs are connected in series across a 220V supply in a room. If one bulb is fused, then remaining bulbs are connected again in series across the same supply. The illumination in the room will be Show Answer

Q206) A wire is broken in four equal parts. A packet is formed by keeping the four wires together. The resistance of the packet in comparison to the resistance of the wire will be Show Answer

Q207) Sensitivity of potentiometer can be increased by Show Answer

Q208) A wire is stretched so as to change its diameter by 0.25%. The percentage change in resistance is Show Answer

Q209) A metallic resistor is connected across a battery. If the number of collisions of the free electrons with the lattice is some how decreased in the resistor (for example by cooling it), the current will Show Answer

Q210) The negative Zn pole of Daniell cell, sending a constant current through a circuit, decreases in mass by 0.13 g in 30 min. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively, the increase in the mass of the positive Cu pole in this time is Show Answer

Q211) Consider four circuits shown in figure. In which circuit power dissipated is greatest. (Neglect the internal resistance of the power supply) Show Answer

Q212) A source of emf E=15V and having negligible internal resistance, is connected to a variable resistance, so that the current in the circuit increases with time as I=1.2t+3. Then, the total charge that will flow in first 5s will be Show Answer

Q213) Two bulbs, one of 50 watt and another of 25 watt are connected in series to the mains. The ratio of the currents through them is Show Answer

Q214) A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively Show Answer

Q215) Three electric bulbs of rating 60 W each are joined in series and then connected to electric mains. The power consumed by these three bulbs will be Show Answer

Q216) In a meter bridge experiment, the ratio of the left gap resistance to right gap resistance is 2:3, the balance point from left is Show Answer

Q217) A battery is charged at a potential of 15 V in 8 hours when the current flowing is 10 A. The battery on discharge supplies a current of 5 A for 15 hours. The mean terminal voltage during discharge is 14 V. The "Watt-hour" efficiency of battery is Show Answer

Q218) The number of dry cells, each of e.m.f. 1.5 volt and internal resistance 0.5 ohm that must be joined in series with a resistance of 20 ohm so as to send a current of 0.6 ampere through the circuit is Show Answer

Q219) Kirchoff’s second law for the analysis of circuit is based on Show Answer

Q220) When a current passes through the junction of two different metals, evolution or absorption of heat at the junction is known as Show Answer

Q221) On passing the current in water voltmeter, hydrogen Show Answer

Q222) A certain current passing through a galvanometer produces a deflection of 100 divisions. When a shunt of one ohm is connected, the deflection reduces to 1 division. The galvanometer resistance is Show Answer

Q223) For measurement of potential difference, potentiometer is preferred in comparison to voltmeter because Show Answer

Q224) Two identical conductors maintained at same temperatures are given potential differences in the ratio 1:2. Then the ratio of their drift velocities is Show Answer

Q225) The mass of ions deposited during a given interval of time in the process of electrolysis depends on Show Answer

Q226) A cell of emf 6 V and resistance 0.5 ohm is short circuited. The current in the cell is Show Answer

Q227) What is the resistance of a carbon resistance which has bands of colours brown, black and brown Show Answer

Q228) The chemical equivalent of copper and zinc are 32 and 108 respectively. When copper and silver voltmeters are connected in series and electric current is passed through for sometime, 1.6 g of copper is deposited. Then, the mass of silver deposited will be Show Answer

Q229) A Copper wire of length 1 m and radius 1 mm is joined in series with an iron wire of length 2 m and radius 3 mm and a current is passed through the wires. The ratio of the current density in the wires. The ratio of the current density in the copper and iron wires is Show Answer

Q230) To draw maximum current from a combination of cells, how should the cells be grouped? Show Answer

Q231) An electric wire of length 'L' and area of cross-section a has resistance R ohm. Another wire of the same material having same length and area of cross-section 4a has a resistance of Show Answer

Q232) When a current flows through a conductor its temperature Show Answer

Q233) A house, served by 220 V supply line, is protected by a 9 A fuse. The maximum number of 60W bulbs in parallel that can be turned on is Show Answer

Q234) Same current is being passed through a copper voltmeter and a silver voltmeter. The rate of increase in weights of the cathode of the two voltmeters will be proportional to Show Answer

Q235) Two resistances R and 2 R are connected in parallel in an electric circuit. The thermal energy developed in in R and 2 R is in the ratio Show Answer

Q236) 3 identical bulbs are connected in series and these together dissipate a power P. If now the bulbs are connected in parallel, then the power dissipated will be Show Answer

Q237) How much current should be passed through a silver voltmeter to deposit 200 gm of silver per hour on the cathode? (Faraday constant = 96500 C/mol and relative atomic mass of silver is 108) Show Answer

Q238) Which of the following graphs shows the variation of thermoelectric power with temperature difference between hot and cold junction in thermocouples? Show Answer

Q239) A given resistor has the following colour scheme of the various strips on it, brown, black, green and silver. Its value in ohm is Show Answer

Q240) A straight conductor of uniform cross-section carries a current i, If s is the specific charge of an electron, the momentum of all the free electrons per unit length of the conductor, due to their drift velocity only is Show Answer

Q241) Two cells A and B are connected in the secondary circuit of a potentiometer one at a time and the balancing length are respectively 400 cm and 440 cm. The emf of the cell A is 1.08V. The emf of the second cell B is volt is Show Answer

Q242) In a potentiometer circuit there is a cell of e.m.f. 2 volt, a resistance of 5 ohm and a wire of uniform thickness of length 1000 cm and resistance 15 ohm. The potential gradient in the wire is Show Answer

Q243) A galvanometer has a resistance of 25 ohm and a maximum of 0.01 A current can be passed through it. In order to change it into an ammeter of range 10 A, the shunt resistance required is Show Answer

Q244) The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 lamps, when not in use? Show Answer

Q245) A strip of copper and another of germanium are cooled from room temperature to 80 K. The resistance of Show Answer

Q246) Flash light equipped with a new set of batteries, produces bright white light. As the batteries wear out Show Answer

Q247) A potentiometer has uniform potential gradient across it. Two cells connected in series (i) to support each other and (ii) to oppose each other are balanced over 6m and 2m respectively on the potentiometer wire. The e.m.f.'s of the cells are in the ratio of Show Answer

Q248) To convert a moving a coil galvanometer (MCG) into a voltmeter Show Answer

Q249) For a given temperature difference which of the following pairs will generate maximum thermo-emf? Show Answer

Q250) The variation between V-i has been shown by V-i graph for heater filament. Show Answer

Q251) A copper voltmeter and a silver voltmeter are connected in series in a circuit. The rate of the increase in the weight of the cathode in the two voltmeters will be in the ratio of Show Answer

Q252) Constantan wire is used in making standard resistances because its Show Answer

Q253) In ballistic galvanometer, the frame in which the coil is wound is non-metallic to Show Answer

Q254) The resistance of an ideal voltmeter is Show Answer

Q255) When an electric heater is switched on, the current flowing through it (i) is plotted against time (t). Taking into account the variation of resistance with temperature, which of the following best represents the resulting curve Show Answer

Q256) If an electric current is passed through a nerve of a man, then man Show Answer

Q257) A meter bridge is used to determine the resistance of an unknown wire by measuring the balance point length l. If the wire is replaced by another wire of same material but with double the length and half the thickness, the balancing point is expected to be Show Answer

Q258) All of the following statements are true except Show Answer

Q259) Two wires that are made up of two different materials whose specific resistance are in the ratio 2 : 3, length 3 : 4 and area 4 : 5. The ratio of their resistances is Show Answer

Q260) If a steady current of 100 A is passed then how much time is taken to deposit 0.254 kg of copper on the cathode of copper voltmeter. Use the known value of Faraday constant and relative atomic mass of copper is 63.5. Show Answer

Q261) Two electric bulbs (60W and 100W respectively) are connected in series. The current passing through them is Show Answer

Q262) Heat produced in a wire of resistance R due to current flowing at constant potential difference is proportional to Show Answer

Q263) The resistance of a wire is 20 ohm. It is so stretched that the length becomes three times, then the new resistance of the wire will be Show Answer

Q264) If a wire is stretched to make it 0.1% longer, its resistance will Show Answer

Q265) Two electric bulbs, each designed to operate with a power of 500 W in 220 V line are connected in series in a 110 V line. The power generated by each bulb will be Show Answer

Q266) Two uniform wires A and B are of the same metal and have equal masses. The radius of wire A is twice that of wire B.The total resistance of A and B when connected in parallel is Show Answer

Q267) The colour sequence in a carbon resistor is red, brown, orange and silver. The resistance of the resistor is Show Answer

Q268) In the absence of applied potential, the electric current flowing through a metallic wire is zero because Show Answer

Q269) A bulb of 220 V and 300 W is connected across 110 V circuit. The percentage reduction in power is Show Answer

Q270) By a cell a current of 0.9 A flows through 2 ohm resistor and 0.3 A through 7 ohm resistor. The internal resistance of the cell is Show Answer

Q271) In Wheatstone’s bridge P = 9 ohm, Q = 11 ohm,R = 4 ohm and S = 6 ohm. How much resistance must be put in parallel to the resistance S to balance the bridge? Show Answer

Q272) The resistivity of a wire depends on its Show Answer

Q273) A storage cell is charged by 5 amp D.C. for 18 hours. Its strength after charging will be Show Answer

Q274) In a galvanometer 5% of the total current in the circuit passes through it. If the resistance of the galvanometer is G, the shunt resistance S connected to the galvanometer is Show Answer

Q275) An electric lamp is marked 60 W, 230 V. The cost of kilowatt hour of power is Rs. 1.25. The cost of using this lamp 8 hrs a day for 30 days is Show Answer

Q276) A 200 W and a 100 W bulb, both meant for operation at 220 V are connected in series. When connected to a 220 V supply the power consumed by the combination is Show Answer

Q277) A cell of emf E is connected across a resistance R the potential difference between the terminals of the cell is found to be V volt. Then the internal resistance of the cell must be Show Answer

Q278) Two copper wires have their masses in the ratio 2 : 3 and the lengths in the ratio 3 : 4 the ratio of their resistance is Show Answer

Q279) Two bulbs of 100 W and 200 W working at 220 V are joined in series with 220 V supply. Total power consumed will be Show Answer

Q280) A cell in secondary circuit gives null deflection for 2.5 m length of potentiometer having 10 m length of wire. If the length of the potentiometer wire is increased by 1 m without changing the cell in the primary, the position of the null point now is Show Answer

Q281) The electromotive force of a primary cell is 2 volt. When it is short-circuited it gives a current of 4 ampere. Its internal resistance in ohm is Show Answer

Q282) How many coulombs of electric charge must pass through acidulated water in order to release 22.4 L Of hydrogen at NTP? Show Answer

Q283) If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a Show Answer

Q284) Heat produced (cals) in a resistance R when a current I amperes flows through it for t seconds is given by the expression Show Answer

Q285) The electrolyte used in Lechlanche cell is Show Answer

Q286) The relaxation time in conductors Show Answer

Q287) An electric heater rated 220 V and 550 W is connected to AC mains. The current drawn by it is Show Answer

Q288) An electric heater rated 220 V and 550 W is connected to AC mains. the resistance between the square faces is Show Answer

Q289) Which of the adjoining graphs represents ohmic resistance? Show Answer

Q290) A cylindrical conductor has uniform cross-section. Resistivity of its material increases linearly from left end to right end. If a constant current is flowing through it and at a section distance x from left end, magnitude of electric field intensity is E, which of the following graphs is correct? Show Answer

Q291) How much energy in kilowatt hour is consumed in operating ten 50 watt bulbs for 10 hours per day in a month (30 days) Show Answer

Q292) Ampere hour is the unit of Show Answer

Q293) The equivalent resistance of resistor connected in series is always Show Answer

Q294) Which of the following has a negative temperature coefficient? Show Answer

Q295) The electric bulbs have tungsten filaments of same length. If one of then gives 60 watt and other 100 watt then Show Answer

Q296) When an electrical appliance is switched on, it responds almost immediately, because Show Answer

Q297) If voltage across a bulb rated 220 Volt - 100 Watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is Show Answer

Q298) If potential difference is applied, the drift velocity at temperature T is Show Answer

Q299) In an electric heater 4 amp current passes for 1 minute at potential difference of 250 volt, the power of heater and energy consumed will be respectively Show Answer

Q300) Which of the following characteristics of electron determines the current in a conductor? Show Answer

Q301) For comparing the e.m.f.'s of two cells with a potentiometer, a standard cell is used to develop a potential gradient along the wires. Which of the following possibilities would make the experiment unsuccessful? Show Answer

Q302) Three resistances each of 1 ohm, are joined in parallel. Three such combinations are put in series, then the resultant resistance will be Show Answer

Q303) Two wires of the same material and having same uniform area of cross-section are connected in series in an electrical circuit. The masses of the wires are m and 2m. When a current I flows in the circuit, the heats produced by them in a given time are in ratio Show Answer

Q304) A copper and a chromium voltmeter are connected in series with a battery. It found that in half an hour 0.475 g of copper and 0.130 g of chromium have been deposited. The ECE ratio of copper and chromium is Show Answer

Q305) A 12 HP motor has to be operated 8 h/day. How much will it cost at the rate of 50 paise/kWh in 10 days? Show Answer

Q306) Combination of two identical capacitors, a resistor R and a DC voltage source of voltage 6 V is used in an experiment onC-R circuit. It is found that for a parallel combination of the capacitor the time in which the voltage of the fully charged combination reduces to half its original voltage is 10s. For series combination the time needed for reducing the voltage of the fully charged series combination by half is Show Answer

Q307) Two filaments of same length are connected first in series and then in parallel. For the same amount of main current flowing the ratio of the heat produced is Show Answer

Q308) The resistance will be least in a wire with dimension Show Answer

Q309) Three resistors are connected to form the sides of a triangle ABC, the resistance of the sides AB, BC and CA are 40 ohm, 60 ohm and 100 ohm respectively. The effective resistance between the points A and B in ohm will be Show Answer

Q310) A potential difference is applied across the ends of a metallic wire. If the potential difference is doubled, the drift velocity will Show Answer

Q311) A silver voltameter of resistance 2 ohm and a 3 ohm resistor are connected in series across a cell. If a resistance of 2 ohm is connected in parallel with the voltameter, then the rate of deposition of silver Show Answer

Q312) A nichrome wire 50 cm long and one square millimetre cross-section carries a current of 4A when connected to a 2V battery. The resistivity of nichrome wire in ohm metre is Show Answer

Q313) If an ammeter is connected in parallel to a circuit, it is likely to be damaged due to excess Show Answer

Q314) A source of a primary cell is 2 V. What is the short circuited it provides 4 A current, then the internal resistance of cell will be Show Answer

Q315) The current inside a copper voltameter Show Answer

Q316) A thermocouple is formed by two metals X and Y, metal X comes earlier to Y in Seebeck series. If temperature of hot junction increases beyond the temperature of inversion, then direction of current in thermocouple will be from Show Answer

Q317) In a meter bridge experiment, null point is obtained at 20 cm from one end of the wire when resistance X is balanced against another resistance Y. If X < Y, then where will be the new position of the null point from the same end, if one decides to, balance a resistance of 4X against Y? Show Answer

Q318) In a potentiometer arrangement, a cell of emf 1.5V gives a balance point at 27cm length of wire. If the cell is replaced by another cell and balance point shifts to 54cm, the emf of the second cell is Show Answer

Q319) By ammeter, which of the following can be measured Show Answer

Q320) Constant current is flowing through a linear conductor of non-uniform area of cross-section. The charge flowing per second through the area of conductor at any cross-section is Show Answer

Q321) Two wires of same material have length L and 2 L and cross-sectional areas 4 A and A respectively. The ratio of their specific resistances would be Show Answer

Q322) n identical cells each of e.m.f. E and internal resistance r are connected in series. An external resistance R is connected in series to this combination. The current through R is Show Answer

Q323) As the temperature of hot junction increases, the thermo e.m.f Show Answer

Q324) One kilowatt hour is equal to Show Answer

Q325) 2, 4 and 6 S are the conductance of three conductors. When they are joined in parallel, their equivalent conductance will be Show Answer

Q326) What is immaterial for an electric fuse? Show Answer

Q327) An electric bulb is rated 220 V - 100 W. The power consumed by it when operated on 110 V will be Show Answer

Q328) The electron drift speed is small and the charge of the electron is also small but still, we obtain large current in a conductor. This is due to Show Answer

Q329) The relation between Faraday’s constant F, electron charge e and avogadro number N is Show Answer

Q330) A voltmeter has resistance of 2000 ohm and it can measure upto 2 V. If we want to increase its range to 10 V, then the required resistance in series will be Show Answer

Q331) A potential difference V is applied to a copper wire of length l and thickness d. If V is doubled, the drift velocity Show Answer

Q332) The maximum power dissipated in an external resistance R, when connected to a cell of emf E and internal resistance r, will be Show Answer

Q333) A galvanometer acting as a voltmeter should have Show Answer

Q334) With a potentiometer null point were obtained at 140 cm and 180 cm with cells of emf 1.1 V and one unknown X volt. Unknown emf is Show Answer

Q335) In an experiment of meter bridge, a null point is obtained at the centre of the bridge wire. When a resistance of 10 ohm is connected in one gap, the value of resistance in other gap is Show Answer

Q336) If an ammeter is joined in parallel through a circuit, it can be damaged due to excess Show Answer

Q337) Two wires have resistances R and 2 R. When both are joining in series and in parallel, then ratio of heats generated in these situations on applying the same voltage, is Show Answer

Q338) On increasing the temperature of a conductor, its resistance increases because the Show Answer

Q339) A steady current of 5 amps is maintained for 45 mins. During this time it deposits 4.572 gm of zinc at the cathode of a voltmeter. E.C.E. of zinc is Show Answer

Q340) How much current should be passed through acidified water for 100s to liberate 0.224 L of hydrogen? Show Answer

Q341) A metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases, the drift velocity of the electron in it Show Answer

Q342) Three resistors each of 2 ohm are connected together in a triangular shape. The resistance between any two vertices will be Show Answer

Q343) All the edges of a block with parallel faces are unequal. Its tangent edge is twice its shortest edge. The ratio of the maximum to minimum resistance between parallel faces is Show Answer

Q344) A current of 16 ampere flows through molten NaCl for 10 minute. The amount of metallic sodium that appears at the negative electrode would be Show Answer

Q345) Two rods of same material and length have their electric resistances in ratio 1 : 2. When both rods are dipped in water, the correct statement will be Show Answer

Q346) 1 kg piece of copper is drawn into a wire 1 mm thick, and another piece into a wire 2 mm thick. Compare the resistance of these wires Show Answer

Q347) Faraday’s 2nd law states that mass deposited on the electrode is directly proportional to Show Answer

Q348) What is the volume of hydrogen liberated at NTP by the amount of charge which liberates 0.3175 g of copper? Show Answer

Q349) A 60 watt bulb operates on 220 V supply. The current flowing through the bulb is Show Answer

Q350) Consider a rectangular slab of length L and area of cross section A. A current I is passed through it. If the length is doubled, the potential drop across the end faces Show Answer

Q351) A thick wire is stretched, so that its length become two times. Assuming that there is no change in its density, then what is the ratio of change in resistance of wire to the initial resistance of wire? Show Answer

Q352) A heater of 220 V heats a volume of water in 5 min. The same heater when connected to 110 V heats the same volume of water in (minute) Show Answer

Q353) A wire 100cm long and 2.0 mm diameter has a resistance of 0.7 ohm, the electrical resistivity of the material is Show Answer

Q354) The potential gradient along the length of a uniform wire is 10 volt/metre. B and C are the two points at 30 cm and 60 cm point on a meter scale fitted along the wire. The potential difference between B and C will be Show Answer

Q355) An electric bulb rated for 500 W at 100V is used in a circuit having a 200 V supply. The resistance R that must be put in series with the bulb, so that the bulb drawn 500 W is Show Answer

Q356) The two bulbs, one of 60 W and other 200 W are connected in series to a 200 volt line, then Show Answer

Q357) A capacitor is connected to a cell of emf E having some internal resistance r. The potential difference across the Show Answer

Q358) Which of the following statements is wrong? Show Answer

Q359) Two bulbs when connected in parallel to a source take 60 W each. The total power consumed when they are connected in series with the same source is Show Answer

Q360) An electric heater kept in vacuum is heated continuously by passing electric current. Its temperature Show Answer

Q361) There are n similar conductors each of resistance R. The resultant resistance comes out to be x when connected in parallel. If they are connected in series, the resistance comes out to be Show Answer

Q362) The production of e.m.f. by maintaining a difference of temperature between the two junctions of two different metals is known as Show Answer

Q363) Two identical heaters rated 220 volt,1000 watt are placed in series with each other across 220 volt lines. If resistance does not change with temperature, then the combined power is Show Answer

Q364) When current flows through a conductor, then the order of drift velocity of electrons will be Show Answer

Q365) n equal resistors are first connected in series and then connected in parallel. What is the ratio of the maximum to the minimum resistance Show Answer

Q366) A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be Show Answer

Q367) In Cu-Fe couple, the flow of current at the temperature of inversion is Show Answer

Q368) In voltaic air cell if 5g zinc is consumed, how many ampere hours shall we get? Show Answer

Q369) When a metal conductor connected to the left gap of a meter bridge is heated, the balancing point Show Answer

Q370) A wire of resistance R is elongated n- fold to make a new uniform wire. The resistance of new wire Show Answer

Q371) When connected across the terminals of a cell, a voltmeter measures 5V and a connected ammeter measures 10 A of current. A resistance of 2 ohm is connected across the terminals of the cell. The current flowing through this resistance will be Show Answer

Q372) Two wires 'A' and 'B' of the same material have their lengths in the ratio 1∶2 and radii in the ratio 2∶1. The two wires are connected in parallel across a battery. The ratio of the heat produced in 'A' to the heat produced in 'B' for the same time is Show Answer

Q373) A solenoid is at potential difference of 60 V and current flowing through it is 15 ampere, then the resistance of coil will be Show Answer

Q374) Five equal resistors when connected in series dissipated 5 W power. If they are connected in parallel, the power dissipated will be Show Answer

Q375) A uniform wire of resistance R is uniformly compressed along its length, until its radius becomes n times the original radius. Now resistance of the wire becomes Show Answer

Q376) Ohm's law is true Show Answer

Q377) A wire has a resistance of 12 ohm. It is bent in the form of equilateral triangle. The effective resistance between any two corners of the triangle is Show Answer

Q378) A battery is made by connecting 6 cells each having capacity 5 Ah at 1.5V. The battery will have capacity equal to Show Answer

Q379) A given carbon resistor has the following colour code of the various strips: orange, red, yellow and gold. The value of resistance in ohm is Show Answer

Q380) Twelve wires of equal resistance R are connected to form a cube. The effective resistance between two opposite diagonal ends will be Show Answer

Q381) The maximum power drawn out of the cell from a source is given by (where r is internal resistance) Show Answer

Q382) A galvanometer of resistance, G, is shunted by a resistance S ohm. To keep the main current in the circuit unchanged, the resistance to be put in series with the galvanometer is Show Answer

Q383) A bulb of 220 V and 300 W is connected across 110 V circuit, the percentage reduction in power is Show Answer

Q384) A voltmeter having a resistance of 998 ohm is connected to a cell of e.m.f. 2 volt and internal resistance 2 ohm. The error in the measurement of e.m.f. will be Show Answer

Q385) Twelve cells, each having emf E volts are connected in series and kept in a closed box. Some of these cells are wrongly connected with positive and negative terminals reversed. This 12-cell battery is connected with an ammeter, an external resistance R ohm and a two-cell battery (two cells of the same type used earlier, connected perfectly in series). The current in the circuit when the 12-cell battery and 2-cell battery aid each other is 3A and 2A when they oppose each other. Then, the number of cell in 12-cell battery that are connected wrongly is Show Answer

Q386) A bulb has specification of one kilowatt and 250 volts, the resistance of bulb is Show Answer

Q387) The resistance of a wire is R. If the length of the wire is doubled by stretching, then the new resistance will be Show Answer

Q388) Three resistances each of 4Ω are connected in the form of an equilateral triangle. The effective resistance between any two corners is Show Answer

Q389) To deposit one gm equivalent of an element at an electrode, the quantity of electricity needed is Show Answer

Q390) In a thermocouple, which of the following statements is not true Show Answer

Q391) A voltmeter essentially consists of Show Answer

Q392) The resistance of ideal voltmeter is Show Answer

Q393) An energy source will supply a constant current into, the load, if its internal resistance is Show Answer

Q394) In water voltmeter, the electrolysis of …… takes place Show Answer

Q395) When a resistance of 2 ohm is connected across the terminals of a cell, the current is 0.5 ampere. When the resistance is increased to 5 ohm, the current is 0.25 ampere. The internal resistance of the cell is Show Answer

Q396) The value of current required to deposit 0.972 gm of chromium in 3 hours if the E.C.E. of chromium is 0.00018 gm per coulomb, is Show Answer

Q397) Peltier coefficient for the junction of a pair of metals is proportional to Show Answer

Q398) A fuse wire of circuit cross-section and having diameter of 0.4 mm, allows 3 A of current to pass through it. But if another fuse wire of same material and circular cross-section and having diameter of 0.6 mm is taken, then the amount of current passed through the fuse is Show Answer

Q399) Fifty electric bulbs, all identical, are connected in series across the mains of a 220 V supply. After one bulb is fused, the remaining 49 bulbs connected in series across the same mains. The illumination will be Show Answer

Q400) The resistance of a cell does not depend on Show Answer

Q401) Identify the incorrect statement regarding a superconducting wire Show Answer

Q402) Under what condition will the strength of current in a wire of resistance R be the same for connection is n series or in parallel of n identical cells each of the internal resistance r, when Show Answer

Q403) If three bulbs 60 W, 100 W and 200 W are connected in parallel, then Show Answer

Q404) Which of the following are true, when the cells are connected in series? Show Answer

Q405) A milli voltmeter of 25 milli volt range is to be converted into an ammeter to 25 ampere range. The value (in ohm) of necessary shunt will be Show Answer

Q406) Two identical heaters of 220V , 1000 W are placed in parallel with each other across 220V line, then the combined power is Show Answer

Q407) The resistance of a straight conductor does not depend on its Show Answer

Q408) The rate of increase of thermo e.m.f. with temperature at the neutral temperature of a thermocouple Show Answer

Q409) When 1 A current flows for 1 min through a silver voltmeter, it deposits 0.067 g of silver on the cathode, then how much charge will flow to deposit 108 g of silver? Show Answer

Q410) Consider the following two statements A and B, and identify the correct choice out of given answers
A. Thermo e.m.f. is minimum at neutral temperature of a thermocouple
B. When two junctions made of two different metallic wires are maintained at different temperatures, an electric current is generated in the circuit. Show Answer

Q411) The resistance of an incandescent lamp is Show Answer

Q412) A wire of resistance 5.5 ohm is drawn out uniformly so that its length is increased twice. Then its new resistance is Show Answer

Q413) A battery of e.m.f. 3 volt and internal resistance 1.0 ohm is connected in series with copper voltmeter. The current flowing in the circuit is 1.5 amperes. The resistance of voltmeter will be Show Answer

Q414) Potentiometer measures the potential difference more accurately than a voltmeter because Show Answer

Q415) The thermocouple among the following that can produce maximum thermo-emf for the same temperature difference between the junction is Show Answer

Q416) In a meter bridge, the balancing length from the left end (standard resistance of one ohm is in the right gap) is found to be 20 cm. The value of the unknown resistance is Show Answer

Q417) Water boils in an electric kettle in 15 minutes after switching on. If the length of the heating wire is decreased to 2/3 of its initial value, then the same amount of water will boil with the same supply voltage in Show Answer

Q418) Charge Q is divided into two parts which are then kept some distance apart. The force between them will be maximum if the two parts are having the charge Show Answer

Q419) A steady current is set up in a metallic wire of non-uniform cross-section. How is the rate of flow of electrons (R) related to the area of cross-section (A)? Show Answer

Q420) If a current is allowed to pass through a circuit consisting of two dissimilar metals, there is either evolution or absorption of heat at the junction, depending upon the direction of the current. The effect is known as Show Answer

Q421) Two electric bulbs A and B are rated as 60 W and 100 W. They are connected in parallel to the same source. Then Show Answer

Q422) The atomic weight of silver and copper are 108 and 64. A silver voltmeter and a copper voltmeter are connected in series and when current is passed 10.8 gm of silver is deposited. The mass of copper deposited will be Show Answer

Q423) In order to increase the sensitivity of galvanometer Show Answer

Q424) 1) The product of a volt and a coulomb is a joule
(2) The product of a volt and an ampere is a joule/second
(3) The product of volt and watt is horse power
(4) Watt-hour can be measured in terms of electron volt
State if Show Answer

Q425) Two bulbs consume same power when operated at 200 V and 300 V respectively. When these bulbs are connected in series across a DC source of 400 V then the ratio of power consumed across them is Show Answer

Q426) 100 cells each of e.m.f. 5 V and internal resistance 1 ohm are to be arranged so as to produce maximum current in a 25 ohm resistance. Each row is to contain equal number of cells. The number of rows should be Show Answer

Q427) If 96500 coulombs of electricity liberates one gram equivalent of any substance, the time taken for a current of 0.15 amperes to deposit 20mg of copper from a solution of copper sulphate is (Chemical equivalent of copper = 32) Show Answer

Q428) Two bulbs when connected in parallel to a source take 100 W each. The total power consumed when they are connected in series with the same source is Show Answer

Q429) A current of 2.0 ampere passes through a cell of e.m.f. 1.5 volt having internal resistance of 0.15 ohm. The potential difference measured, in volt, across both the ends of the cell will be Show Answer

Q430) The resistance of a heater coil is 110 ohm. A resistance R is connected in parallel with it and the combination is joined in series with a resistance of 11 ohm to a 220 volt main line. The heater operates with a power of 110 watt. The value of R in ohm is Show Answer

Q431) A piece of fuse wire melts when a current of 15 ampere flows through it. With this current, if it dissipates 22.5 W, the resistance of fuse wire will be Show Answer

Q432) Two identical electric lamps marked 500 W, 220 V are connected in series and then joined to a 110 V line. The power consumed by each lamp is Show Answer

Q433) The potentiometer is superior to a voltmeter for measuring a potential difference because Show Answer

Q434) Two wires A and B of same material and mass have their lengths in the ratio 1:2. On connecting them to the same source, the rate of heat dissipation in B is found to be 5W. The rate of heat dissipation in A is Show Answer

Q435) The heat produced by a 100 W heater in 2 min will be equal to Show Answer

Q436) In a conductor 4 coulomb of charge flows for 2 seconds. The value of electric current will be Show Answer

Q437) Silver and copper voltameters are connected in parallel with a battery of emf 12 V. In 30 min 1 g of silver and 1.8 g of copper are liberated. The energy supplied by the battery is Show Answer

Q438) The resistivity of a wire Show Answer

Q439) The potential difference in open circuit for a cell is 2.2 volt. When a 4 ohm resistor is connected between its two electrodes the potential difference becomes 2 volt. The internal resistance of the cell will be Show Answer

Q440) If the electric current through an electric bulb is 3.2 A, the number of electrons flow through it in one second is Show Answer

Q441) Find the true statements Show Answer

Q442) A battery of emf E has an internal resistance r. A variable resistance R is connected to the terminals of the battery. A current i is drawn from the battery. V is the terminal potential difference. If R alone is gradually reduced to zero, which of the following best describes i and V? Show Answer

Q443) A battery is charged at a potential of 15 V for 8 hours when the current flowing is 10 A. The battery on discharge supplies a current of 5 A for 15 hours. The mean terminal voltage during discharge is 14 V. The "Watt-hour" efficiency of the battery is Show Answer

Q444) For electroplating a spoon, it is placed in the voltmeter at Show Answer

Q445) A wire of resistance R is divided in 10 equal parts. These parts are connected in parallel, the equivalent resistance of such connection will be Show Answer

Q446) Two electroplating cells, one of silver and another of aluminium are connected in series. The ratio of the number of silver atoms to that of aluminium atoms deposited during time t will be Show Answer

Q447) An electric kettle boils some water in 16 min. Due to some defect, it becomes necessary to remove 10% turns of heating coil of the kettle. Now, how much time will it take to boil the same of water? Show Answer

Q448) A cold-water pipe and a hot-water pipe are both made of copper and are initially electrically isolated. In which one of the following arrangements will the galvanometer indicate a thermo-electric current? Show Answer

Q449) The resistance of a galvanometer is 90 ohm. If only 10 percent of the main current may flow through the galvanometer, in which way and of what value, a resistor is to be used Show Answer

Q450) A 5.0 A current is setup in an external circuit by a 6.0 storage battery for 6.0 min. The chemical energy of the battery is reduced by Show Answer

Q451) An electric bulb is marked 100 W, 230 V. If the supply voltage drops to 115 V, what is the total energy produced by the bulb in 10 min? Show Answer

Q452) Three bulbs of 40 W, 60 W, 100 W are arranged in series with 220 volt supply. Which bulb has minimum resistance Show Answer

Q453) The conductivity of a superconductor is Show Answer

Q454) A colour coded carbon resistor has the colours orange, blue, green and silver. Its resistance value and tolerance percentage respectively are Show Answer

Q455) For driving a current of 2 A for 6 minutes in a circuit, 1000 J of work is to be done. The e.m.f. of the source in the circuit is Show Answer

Q456) A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1V, the resistance in Ohm’s needed to be connected in series with the coil will be Show Answer

Q457) Kirchhoff’s second law is based on the law of conservation of Show Answer

Q458) A battery of e.m.f. 10 V and internal resistance 0.5 ohm is connected across a variable resistance R. The value of R for which the power delivered in it is maximum is given by Show Answer

Q459) Which factor is immaterial for the wire used in electric fuse? Show Answer

Q460) An ammeter of 5 ohm resistance can read 5 mA. If it is to be used to read 100 volt, how much resistance is to be connected in series Show Answer

Q461) The potential difference across the terminals of a battery is 50 V when 11 A current is drawn and 60 V when 1 A current is drawn. The e.m.f. and the internal resistance of the battery are Show Answer

Q462) Two electric bulbs have ratings respectively of 25 W, 220 V and 100 W, 220 V. If the bulbs are connected in series with a supply of 440, which bulb will fuse? Show Answer

Q463) Express which of the following setups can be used to verify Ohm’s law Show Answer

Q464) The thermo emf produced in a thermo-couple is 3 microvolt per degree centigrade. If the temperature of the cold junction is 20℃ and the thermo emf is 0.3 millivolt, the temperature of the hot junction is Show Answer

Q465) Metals have Show Answer

Q466) When a charged particle of charge e revolves in circular orbit of radius r with frequency n, then orbital current will be Show Answer

Q467) If a 2 kW boiler is used everyday for 1 hour, then electrical energy consumed by boiler in thirty days is Show Answer

Q468) A steady current i is flowing through a conductor of uniform cross-section. Any segment of the conductor has Show Answer

Q469) A coil takes 15 min to boil a certain amount of water; another coil takes 20 min for the same process. Time taken to boil the same amount of water when both coils are connected in series Show Answer

Q470) To liberate two litres of hydrogen at 222.4 atmosphere from acidulated water the quantity of electricity that must pass through is Show Answer

Q471) A galvanometer having a resistance of 8 ohm is shunted by a wire of resistance 2 ohm. If the total current is 1 amp, the part of it passing through the shunt will be Show Answer

Q472) If two electric bulbs have 40 W and 60 W rating at 220 V, then the ratio of their resistances will be Show Answer

Q473) Forty electric bulbs are connected in series across a 220 V supply. After one bulb is fused, the remaining 39 are connected again in series across the same supply. The illumination will be Show Answer

Q474) A heater draws a current of 2A when connected to a 250 V source. The rate of energy dissipation is Show Answer

Q475) A heater coil is cut into two parts of equal length and one of them is used in the heater. The ratio of the heat produced by this half coil to that by the original coil is Show Answer

Q476) If two wires having resistances R and 2R both are joined in series and in parallel, then ratio of heat generated in this situation, applying the same voltage is Show Answer

Q477) What determines the emf between the two metals placed in an electrolyte? Show Answer

Q478) A small power station supplies electricity to 5000 lamps connected in parallel. Each lamp has a resistance of 220 and is operated at 220 V. The total current supplied by the station is Show Answer

Q479) An emf of 0.9 V is generated when the temperature difference hot and cold junction of thermocouple is 75 K. Assuming that the thermo emf is directly proportional to the temperature difference, the extent to which the thermo emf will change when the cold junction is heated up by 15 K is Show Answer

Q480) If the balance point is obtained at the 35 th cm in a meter bridge, the resistances in the left and right gaps are in the ratio of Show Answer

Q481) A lead acid accumulatory (storage battery) is connected to a battery charge for over night charging. Which of the following observations will indicate that the battery was partly charged during the next morning Show Answer

Q482) In a thermocouple, the temperature that does not depend on the temperature of the cold junction is called Show Answer

Q483) A current I is passed for a time t through a number of voltmeters. If m is the mass of a substance deposited on an electrode and z is its electrochemical equivalent, then Show Answer

Q484) A thermocouple is made from two metals, Antimony and Bismuth. If one junction of the couple is kept hot and the other is kept cold, then, an electric current will Show Answer

Q485) Electroplating does not help in Show Answer

Q486) In a circuit 5 percent of total current passes through a galvanometer. If resistance of the galvanometer is G then value of the shunt is Show Answer

Q487) When a current I flows through a wire, the drift velocity of the electrons is v. When current 2I flows through another wire of the same material having double the length and double the area of cross-section, the drift velocity of the electrons will be Show Answer

Q488) A cell of e.m.f. E connected with an external resistance R, then p.d. across cell is V. The internal resistance of cell will be Show Answer

Q489) An external resistance R is connected to a battery of e.m.f. V and internal resistance r. The joule heat produced in resistor R is maximum when R is equal to Show Answer

Q490) A Daniel cell is balanced on 125cm length of a potentiometer wire. Now the cell is short-circuited by a resistance 2 ohm and the balance is obtained at 100 cm. The internal resistance of the Daniel cell is Show Answer

Q491) A moving coil galvanometer is converted into an ammeter reading upto 0.03 A by connecting a shunt of resistance 4r across it and into an ammeter reading upto 0.06 A when a shunt of resistance r is connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used Show Answer

Q492) A 25 watt, 220 volt bulb and a 100 watt, 220 volt bulb are connected in series across a 220 volt lines. Which electric bulb will glow more brightly Show Answer

Q493) The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then Show Answer

Q494) A coil develops heat of 800 cal/sec. When 20 volts is applied across its ends. The resistance of the coil is (1 cal = 4.2 joule) Show Answer

Q495) When the temperature difference between hot and cold junctions of a thermo-couple is 100 K an emf of 1 V is generated. Assume the cold junction is heated by 20 K, the percentage change in thermo emf is Show Answer

Q496) The amount of charge required to liberate 9 gm of aluminium (atomic weight =27 and valency = 3) in the process of electrolysis is (Faraday’s number =96500 coulombs/gm equivalent) Show Answer

Q497) In a potentiometer, the null points are received at 7th wire. If now we have to change the null points at 9th wire, what should we do? Show Answer

Q498) In a copper voltmeter experiment, current is decreased to one-fourth of the initial value but is passed for four times the earlier duration. Amount of copper deposited will be Show Answer

Q499) A 500 W heating unit is designed to operate from a 115 volt line. If the line voltage drops to 110 volt, the percentage drop in heat output will be Show Answer

Q500) The temperature at which thermal electric power of a thermo couple becomes zero is called Show Answer

Q501) A thermister is dipped in a bath whose temperature is to be measured. When the temperature increase the current also increase, because of decreases in Show Answer

Q502) When the current i is flowing a conductor, the drift velocity is v. If 2i current is flowed through the same metal but having double the area of cross-section, then the drift velocity will be Show Answer

Q503) The material of wire of potentiometer is Show Answer

Q504) If two identical heaters each rated as (1000 W-220 V) are connected in parallel to 220 V, then the total power consumed is Show Answer

Q505) It is possible that any some constant value of emf, but the potential difference between the plates is zero? Show Answer

Q506) A current of two ampere is flowing through a cell of e.m.f. 5 volt and internal resistance 0.5 ohm from negative to positive electrode. If the potential of negative electrode is 10 V, the potential of positive electrode will be Show Answer

Q507) The resistance of the filament of a lamp increases with the increase in temperature. A lamp rated 100 W and 200 V is connected across 220 V power supply. If the voltage drops by 10%, then the power of the lamp will be Show Answer

Q508) An ammeter gives full scale deflection when current 1.0 A is passed in it. To convert it into 10 A range ammeter, the ratio of its resistance and the shunt resistance will be Show Answer

Q509) A storage battery has e.m.f. 15 volt and internal resistance 0.05 ohm. Its terminal voltage when it is delivering 10 ampere is Show Answer

Q510) If 10 A deposits 10.8 g of silver in 25 min, how much copper would deposit when 9 A current flows for 20 min.? Show Answer

Q511) A constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if Show Answer

Q512) A silver and a zinc voltmeter are connected in series and a current I is passed through them for a time t, liberating w gram of zinc. The weight of silver deposited is nearly Show Answer

Q513) When current is passed in antimony-bismuth couple, then Show Answer

Q514) 12 cells each having same emf are connected in series with some cells wrongly connected. The arrangement is connected in series with an ammeter and two cells which are in series. Current is 3 A when cells and battery aid each other and is 2 A when cells and battery oppose each other. The number of cells wrongly connected is Show Answer

Q515) Equal amounts of a metal are converted into cylindrical wire of different lengths L and cross-sectional area A. The wire with the maximum resistance is the one, which has Show Answer

Q516) What will happen when a 40 watt, 220 volt lamp and 100 watt, 220 volt lamp are connected in series across 40votl supply Show Answer

Q517) The two ends of a uniform conductor are joined to a cell of e.m.f. E and some internal resistance. Starting from the midpoint P of the conductor, we move in the direction of current and return to P. The potential V at every point on the path is plotted against the distance covered (x). Which of the following graphs best represents the resulting curve? Show Answer

Q518) How many calories of heat will be produced approximately in a 210 W electric bulb in 5 min? Show Answer

Q519) Resistors of 1, 2, 3 ohm are connected in the form of a triangle. If a 1.5 volt cell of negligible internal resistance is connected across 3 ohm resistor, the current flowing through this resistance will be Show Answer

Q520) An electric kettle has two heating coils. When one coil is used, water in the kettle boils in 5 minutes, while when second coil is used, same water boils in 10 minutes. If the two coils, connected in parallel are used simultaneously, the same water will boil in time Show Answer

Q521) A 25 W and 100 W bulbs are joined in series and connected to the mains. Which bulb will glow brighter? Show Answer

Q522) A battery has e.m.f. 4 V and internal resistance r. When this battery is connected to an external resistance of 2 ohm, a current of 1 amp.flows in the circuit. How much current will flow if the terminals of the battery are connected directly Show Answer

Q523) The thermistors are usually made of Show Answer

Q524) The thermistors are usually made of, if length is doubled, the drift velocity Show Answer

Q525) The value of internal resistance of an ideal cell is Show Answer

Q526) Two bulbs 25 W, 220 V and 100 W, 220 V are given. Which has higher resistance? Show Answer

Q527) We have two wires A and B of same mass and same material. The diameter of the wire A is half of that B. If the resistance of wire A is 24 ohm then the resistance of wire B will be Show Answer

Q528) A heater of 220 V heats a volume of water in 5 min time. A heater of 110 V heats the same volume of water is Show Answer

Q529) Which of the following is not reversible? Show Answer

Q530) The following four wires are made of the same material and are at the same temperature. Which one of them has highest electrical resistance? Show Answer

Q531) As the temperature rises the resistance offered by metal Show Answer

Q532) Pick out the wrong statement Show Answer

Q533) When the length and area of cross-section both are doubled, then its resistance Show Answer

Q534) The masses of three wires of copper are in the ratio 1:3:5 and lengths are in the ratio 5:3:1. Then the ratio of their electrical resistances are Show Answer

Q535) Electric power is transmitted over long distances through conducting wires at high voltage because Show Answer

Q536) Two bulbs of 250 V and 100 W are first connected in series and then in parallel with a supply of 250 V. Total power in each of the case will be respectively Show Answer

Q537) A 50 ohm galvanometer gets full scale deflection when a current of 0.01 A passes through the coil. When it is converted to a 10 A ammeter, the shunt resistance is Show Answer

Q538) In a wire of circular cross-section with radius r, free electrons travel with a drift velocity V when a current I flows through the wire. What is the current in another wire of half the radius and of the same material when the drift velocity is 2V Show Answer

Q539) One end each of a resistance r capacitor C and resistance 2r are connected together. The other ends are respectively connected to the positive terminals of batteries, P, Q, R having respectively emf’s E, E and 2E. the negative terminals of the batteries are then connected together. In this circuit, with steady current the potential drop across the capacitor is Show Answer

Q540) The speed at which the current travels, in a conductor, is nearly Show Answer

Q541) If the length of filament of a heater is reduced by 10%, the power of the heater will Show Answer

Q542) The electric current passing through a metallic wire produces heat because of Show Answer

Q543) According to Joule’s law, if the potential difference across a conductor having a material of specific resistance remains constant, then the heat produced in the conductor is directly proportional to Show Answer

Q544) n conducting wires of same dimensions but having resistivites 1, 2, 3,…..n are connected in series. The equivalent resistivity of the combinations is Show Answer

Q545) If a wire of resistance 20Ω is covered with ice and a voltage of 210 V is applied across the wire, then the rate of melting of ice is0.85g/s Show Answer

Q546) The length of a given cylindrical wire is increased by 100%. Due to the consequent decrease in diameter the change in the resistance of the wire will be Show Answer

Q547) The plates of a charged condenser is connected to a voltmeter. If the plates are moved apart, the reading of voltmeter will Show Answer

Q548) If the length of filament of a heater is reduced by 10%, the power of the heater will Show Answer

Q549) A wire of resistance 160 is melted and drawn into a wire one-fourth of its length. The new resistance of the wire will be Show Answer

Q550) Given below are two statements.
Statement I The equivalent resistance of resistors in a series combination is smaller than least resistance used in the combination.
Statement II The resistivity of the material is independent of temperature.
In the light of above statements, choose the most appropriate answer from the options given below.
Show Answer

Q551) In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor Show Answer

Q552) Ratio of thermal energy released in two resistors R and 3R connected in parallel in an electric circuit is Show Answer

Q553) Equivalent resistance between the adjacent corners of a regular n-sided polygon of uniform wire of resistance R would be
Show Answer

Q554) A 1 m long wire is broken into two unequal parts X and Y. The X part of the wire is stretched into another wire W. Length of W is twice the length of X and the resistance of W is twice that of Y. Find the ratio of length of X and Y. Show Answer

Q555) Given below are two statements: one is labelled as Lore Assertion (A) and the other is labelled as Reason (R). Sth Assertion (A) Alloys such as constantan and
manganin are used in making standard resistance coils.
Reason (R) Constantan and manganin have very small value of temperature coefficient of resistance. In the light of the above statements, choose the correct answer from the options given below. Show Answer

Q556) (A) The drift velocity of electrons decreases with the increase in the temperature of conductor.
(B) The drift velocity is inversely proportional to the area of cross-section of given conductor.
(C) The drift velocity does not depend on the applied potential difference to the conductor.
(D) The drift velocity of electron is inversely proportional to the length of the conductor.
(E) The drift velocity increases with the increase in the ns nis temperature of conductor.
Choose the correct answer from the options given below. Show Answer

Q557) An aluminium wire is stretched to make its length, [-0.4% larger. Then, percentage change in resistance is
Show Answer

Q558) A conducting wire of length l, area of cross-section A and electric resistivity p is connected between the terminals of a battery. A potential difference V is developed between its ends, causing an electric current. If the length of the wire of the same material is doubled and the area of cross-section is halved, the resultant current would be Show Answer

Q559) A circuit to verify Ohm's law uses ammeter and voltmeter in series or parallel connected correctly to [2020, 6 Sep Shift-II] the resistor. In the circuit, Show Answer

Q560) A copper wire is stretched to make it 0.5% longer. The percentage change in its electrical resistance, if its volume remains unchanged is Show Answer

Q561) A copper wire is stretched to make it 0.5% longer. The percentage change in its electrical resistance, if its volume remains unchanged is Show Answer

Q562) A 2 W carbon resistor is color coded with green, black, red and brown respectively. The maximum current which can be passed through this resistor is Show Answer

Q563) A uniform wire of length / and radius r has a resistance of 100 Q2. It is recast into a wire of radius r/2. The resistance of new wire will be
Show Answer

Q564) The temperature dependence of resistances of Cu and undoped Si in the temperature range 300-400 K, is best described by Show Answer

Q565) If a wire is stretched to make it 0.1% longer, its
resistance will
Show Answer

Q566) The resistance of the series combination of two resistances is S. When they are joined in parallel, the total resistance is P. IfS=nP, then the minimum possible value of n is Show Answer

Q567) The length of a given cylindrical wire is increased by 100%. Due to the consequent decrease in diameter, the change in the resistance of the wire will be Show Answer

Q568) The length of a metallic wire is increased by 20% and its area of cross-section is reduced by 4%. The percentage change in resistance of the metallic wire is .... Show Answer

Q569) If a copper wire is stretched to increase its length by 20%. The percentage increase in resistance of the wire is ........ %. Show Answer

Q570) The length of a given cylindrical wire is increased to double of its original length. The percentage increase in the resistance of the wire will be ......% Show Answer

Q571) Two identical heater filaments are connected first in o ad parallel and then in series. At the same applied W voltage, the ratio of heat produced in same time for parallel to series will be Show Answer

Q572) An electric bulb of 500 W at 100 V is used in a circuit having a 200 V supply. Calculate the resistance R to be connected in series with the bulb, non so that the power delivered by the bulb is 500 W. Show Answer

Q573) A resistor develops 500 J of thermal energy in 20 s, when a current of 1.5 A is passed through it. If the current is increased from 1.5 A to 3 A, what will be the energy developed in 20 s? Show Answer

Q574) A battery of 3.0 V is connected to a resistor dissipating 0.5 W of power. If the terminal voltage of the battery is 2.5 V, the power dissipated within the internal resistance is Show Answer

Q575) Two equal resistances when connected in series to a battery consume electric power of 60 W. If these resistances are now connected in parallel combination to the same battery, the electric power consumed will be Show Answer

Q576) In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The voltage of the electric mains is 220 V. Then, the minimum current should be Show Answer

Q577) Two electric bulbs marked 25 W-220 V and
100 W-220 V are connected in series to a 440 V supply. Which of the bulbs will fuse?
Show Answer

Q578) An electric bulb is rated 220 V-100 W. The power consumed by it when operated on 110 V will be Show Answer

Q579) A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be Show Answer

Q580) The thermistors are usually made of Show Answer

Q581) Time taken by a 836 W heater to heat 1 L of water
from 10°C to 40°C is
Show Answer

Q582) The negative Zn pole of a Daniell cell, sending a constant current through a circuit, decreases in mass by 0.13 g in 30 minutes. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively the increase in the mass of the positive Cu pole in this time is Show Answer

Q583) A 220 V-1000 W bulb is connected across a 110 V mains supply. The power consumed will be
Show Answer

Q584) The mass of a product liberated on anode in an
electrochemical cell depends on
(Where t is the time period for which the current is passed). Show Answer

Q585) An electrical bulb rated (220 V, 100 W) is connected in series with another bulb rated (220 V, 60 W). If the voltage across combination is 220 V, the power consumed by the 100 W bulb will be about ...... W.
Show Answer

Q586) A resistor develops 300 J of thermal energy in 15 s when a current of 2 A is passed through it. If the current increases to 3 A, the energy developed in 10 s is ......... J. Show Answer

Q587) Two coils require 20 min and 60 min respectively to produce same amount of heat energy when connected separately to the same source. If they are connected in parallel arrangement to the same source; the time
De required to produce same amount of heat by the combination of coils will be ..... min.
Show Answer

Q588) A resistor dissipates 192 J of energy in 1 s when a current of 4 A is passed through it. Now, when the current is doubled, the amount of thermal energy dissipated in 5 s is ........ J. Show Answer

Q589) The energy dissipated by a resistor is 10 mJ in 1s when an electric current of 2 mA flows through it. The resistance is .... ..... Ω. (Round off to the nearest integer) Show Answer

Q590) A cell of internal resistance r drives current through an external resistance R. The power delivered by the cell to the external resistance will be maximum when Show Answer

Q591) An energy source will supply a constant current into An energy source will supply a constant current into Show Answer

Q592) In an electrical circuit, a battery is connected to pass 20 C of charge through it in a certain given time. The potential difference between two plates of the battery is maintained at 15 V. The work done by the battery is ......... J. Show Answer

Q593) With the help of potentiometer we can determine the 00 value of emf of a given cell. The sensitivity of the potentiometer is
A. directly proportional to the length of the potentiometer wire
B. directly proportional to the potential gradient of the wire
C. inversely proportional to the potential gradient of the wire
D. inversely proportional to the length of the potentiometer wire
Show Answer

Q594) Which of the following statements is false? Show Answer

Q595) In a potentiometer arrangement, a cell of emf 1.20 V orgives a balance point at 36 cm length of wire. This Bid cell is now replaced by another cell of emf 1.80 V. o The difference in balancing length of potentiometer wire in above conditions will be ...... cm. Show Answer

Q596) In a potentiometer arrangement, a cell gives a balancing point 75 cm length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf's of two cells, respectively is 3:2, the difference in the balancing length of the potentiometer wire in above two cases will be ...... cm.
Show Answer