Practice Test

1) ________ deals with the motion of particles or bodies without considering cause of motion.

2) The inability of a body to change by itself, its state of rest or state of motion is called ________

3) Action and reaction forces do not cancel each other because

4) The total effect of force when it acts for short interval of time is

5) A ball of mass 250 g moving with 20 m/s strikes a vertical wall and rebounds along the same line with a velocity of 15 m/s. If the time of contact is 0.1 s, the force exerted by the wall on ball is

6) A rider on a horse back falls forward, when the horse suddenly stops. This is due to

7) Momentum is closely related to

8) Which of the following is NOT an example of real force ?

9) ___________ force is defined in order to apply Newton's laws of motion in acceleration motion.

10) A force produced due to interaction between the objects is called ______ force.

11) If the distance between two masses is doubled, gravitational attraction between them

12) Out of the four fundamental forces in nature the weakest force is

13) __________ forces are charge independent.

14) Choose the CORRECT statement.

15) The force between electric charges in relative motion are called

16) Which of the following is NOT the characteristic of gravitational force ?

17) Nuclear force between proton-proton is

18) Newton's law of gravitation is universal because

19) Two identical spheres of gold are close to each other. The gravitational attraction between them is

20) The tidal waves in the sea are primarily due to

21) The electrostatic and gravitational forces are similar because

22) Choose the WRONG statement.

23) When a body goes away from the centre of the earth, its gravitational force goes on decreasing. This is an example of

24) Work is always done on a body when

25) A light and a heavy body have equal K.E. Which body possess greater momentum ?

26) A child pushes the table but fails to displace it. He does

27) A bullet weighing 10 g and moving with a velocity of 300 m/s strikes a 5 kg block of ice and drops dead. The ice block is resting on frictionless level ice. The speed of the block will become

28) Under the action of variable force, at any instant the displacement is

29) Choose the CORRECT statement.

30) If the kinetic energy decreases the work done is

31) A force of F=(0.5x + 12) N acts on a particle. If x is in meter, calculate the work done by the force during the displacement of the particle from x = 0 to x = 4m

32) When two bodies stick together after collision, the collision is said to be

33) The ratio of relative velocity of seperation after collision to the relative velocity of approach before collision between two colliding bodies is

34) A ball of mass 5 kg travelling with velocity of 15 cm/s makes a head on collision with another ball of mass 1 kg which is at rest. After the collision, the speed of the lighter ball is

35) A body of mass 0.1 kg travelling with a velocity of 5m/s, collides head-on with another body of mass 0.2 kg travelling in the same direction with a velocity of 1.2 m/s. If the two bodies stick together after collision, their common velocity is

36) A shell in its flight, explodes into four unequal parts. Which of the following is conserved ?

37) A block of mass m moving at a speed of u collides with another block of mass 2m at rest. The lighter block comes to rest after the collision. The coefficient of restitution is

38) When a massive body suffers an elastic collision with a stationary light body, then massive body approximately come to rest and light body.

39) The coefficient of restitution will NOT have

40) Which of the following is NOT an example of inelastic collision ?

41) A frame of reference which moves with constant velocity with reference to a stationary frame of reference is called

42) A system of co-ordinates of an observer used to describe any motion is called

43) A frame of reference in which Newton's law of inertia does not hold good is called

44) Non- inertial frame of reference have

45) A passenger sitting in a bus moving along a circular path experiences a force which is

46) When a body is at rest, then

47) The turning effect of the applied force does NOT depend upon

48) The ability of a force to produce rotational motion is measured by its turning effect and it is called

49) The direction of torque is given by

50) The unit of moment of force is same as

51) A mass of 10 kg is suspended from a rope wound on a wheel of diameter 40 cm. The torque about the axis of rotation is

52) The moment of the couple is independent of

53) A rigid body is rotating about an axis. The best way to stop it is applying

54) ________ is a pair of equal and parallel forces acting in opposite direction at two different points of a given body

55) The point at which the whole mass of the body is supposed to be concentrated, in order to study motion of the body in accordance with Newton's law of motion is

56) The centre of mass of two particles lies on the line

57) Centre of mass of body lies

58) Three equal masses each of 50 g, are placed at the corners of a right angled isosceles triangle whose two equal sides are 5 cm each. The position of the center of mass of the system is

59) Centre of mass of rectangular lamina lies on

60) Point masses of 2 kg, 3 kg, 5 kg, 7 kg are placed at corners of a square. ABCD respectively whose each side is 1 m long. The position of the center of mass of the system is

61) The centre of mass of a system of two uniform spherical masses of 5 kg and 35 kg with centres of them 0.7 m apart is

62) The weight of the body is maximum at

63) For regular shapes of the small body, which of the following statement is true ?

64) For a circular ring centre of gravity lies

65) A point through which total weight of the body always acts vertically downwards whatever may be the position of the body is

66) When a bus is climbing on hilly road, a standing passenger balances himself by keeping legs apart to achieve balance by keeping

67) Two men A and B supports the ends of a uniform beam 2 m long and weighing 50 kg. A weight of 50 kg hangs from the beam from a point 0.5 m from A. Assuming the bar is horizontal, the load shared by each man is

68) A uniform bar RS weighs 100 g and is 80 cm long. From the end R two masses 50 g and 100 g are hung from the bar at a distance of 10 cm and 60 cm respectively. If the bar is to remain horizontal when balanced on a knife-edge, its position is

69) 6 m long see-saw remains horizontal when two children weighing 20 kg and 30 kg respectively sit at two ends. Where is the see-saw supported ?

70) A steel bar AB of mass 10 kg and length 1 m is kept horizontal by supporting it at the two ends. Two weights of 4 kg and 6 kg are suspended from points of the bar at distances 30 cm and 80 cm respectively from the end A. The reaction at the end A is

71) An athlete runs some distance before taking a long jump, because

72) If the relative displacement between any two particles of a body does not change under the application of force of any magnitude, the body is said to be a

73) A bomb of mass 9 kg explodes into two pieces of mass 3 kg and 6 kg. The velocity of mass 3 kg is 16 m/s, The kinetic energy of mass 6 kg is

74) According to work energy theorem work done by a force in displacing a body measures the change in _____of the body.

75) A ball of mass 0.1 kg makes an elastic head on collision with a ball of unknown mass, initially at rest. If the 0.1 kg ball rebounds at one third of its original speed, the mass of the other ball is

76) If force is applied to a body produces rotational motion in an anti-clock wise sense, the moment of the force is considered as

77) The working of the rocket is based on the principle of

78) Inertial frame of refrence implies that

79) Torque can NOT be given by

80) Force applied to open or close a water tap is an example of

81) The universal constant of gravitation is

82) The range of nuclear force is nearly

83) A bullet leaves the rifle of mass one kg and rifle recoils there by with velocity 30 cm/s. If the mass of the bullet is 3 g, the velocity of the bullet is

84) For perfectly elastic collision

85) A body of mass 1 kg moving with velocity 5m/s collides with another body of mass 2 kg moving with velocity 1.5m/s in opposite direction. If the coefficient of restitution is 0.8, their velocities after collision respectively are

86) A cyclist comes to skidding spot in 10 m. If the opposing force on the cycle due to the road is 200 N. The work done by the road on the cycle is

87) A block of wood moves a distance 5 cm along a straight line under the action of force of 2.5 dyne. If the work done is 6.25 erg, the angle which the force makes with the direction of motion of the body is

88) Which one is WRONG ?

89) The vector form moment of force ( torque) is

90) The position of centre of mass of two particle system is

91) The SI unit of force is

92) Condition of translational equilibrium of a rigid body is

93) A constant force acts on a body of mass 100 g for 4 s. The body starting from rest covers a distance of 0.64 m during this time. The magnitude of force acting on the body is

94) One metallic sphere is at rest. Another metallic sphere hits the first and comes to rest and second sphere moves. The ratio of their masses is

95) A bullet of mass 10 g is fired with a velocity of 100 m/s from a riffle of mass 2.5 kg, the recoil velocity of the rifle is

96) The CORRECT diagram for the work done in moving a body from A and B under the actions of variable force is

97) A bullet of mass 'a' fired with velocity ' b' into block of mass ' c' and remains embedded into it. The final velocity of the system is :

98) A monkey is descending from the branch of tree with constant acceleration. If the breaking strength of the branch is 75 % of the weight of the monkey, the minimum acceleration with which the monkey can slide down is :

99) An unloaded car moving with velocity u on a road can be stopped in a distance ' s ' . If passengers add 40 % to its weight and braking force remains the same the stopping distance at velocity u is now :

100) Two particles A and B initially at rest move towards each other under a mutual force of attraction. At the instant when speed of A is V and speed of B is 2 V , the speed of the centre of mass of system is :

101) A car moving with a speed of 40 km / hr can be stopped by applying brakes after at least 2 m . If the same car is moving at 80 km / hr , what is the least stopping distance ?

102) A toy car consists of three identical compartments A , B and C . It is being pulled by a constant force F . The ratio of the tensions in the strings connecting AB and BC is given by :

103) A disc of mass 10 g is kept floating horizontally by striking 10 marbles per sec each of mass 5 g normally from below . What is the velocity with which the marbles are striking ? ( Assume that marbles rebound with same speed )

104) An open knife edge of mass m is dropped from a height ' h ' on a log of wood and its blade penetrates through a distance S into the wood. The average resistance offered by the wood to the blade is :

105) A uniform chain of length L and mass m is lying on a smooth table. One third of its length is hanging vertically down over the edge of the table. How much work need to be done to pull the hanging part back to the table ?

106) The resultant of two forces , one double than the other in magnitude, is perpendicular to the smaller of the two forces. The angle between two forces is :

107) A body of mass M rests on a floor. It is just made to slide by applying the minimum necessary force and the same force continue to act afterwards. If the coefficient of static and dynamic friction are 0.4 and 0.3 , then the acceleration of the body is :

108) An inclined plane is inclined at an angle ? when the block placed on it is just at the point of moving down the plane. If the initial velocity of projection above the plane is u, the distance up to which the block can rise up is :

109) Two bodies of masses m and 4 m are moving with equal kinetic energy. The ratio of their linear momenta is :

110) A rope of length L is pulled with a constant force F . If T is the tension in the rope at a point distant x from the end where the force is applied, then value of T is :

111) A 20 g bullet pierces through a plate of mass 1 kg and then comes to rest inside a second plate of mass 2.98 kg . It is found that two plates initially at rest, now move with same velocity of the bullet when it is between the two plates. Assume the masses of the plates to remain constant even on striking the bullet.

112) A small rocket is ejecting 0.05 kg / sec of gases with a velocity 400 m / s . The accelerating force is :

113) A body of mass 4 kg is hung on the hook of a spring balance mounted vertically in a lift . If the lift is moving up with an acceleration due to gravity the reading of the spring balance is :

114) A weight is suspended from the ceiling of a lift by a spring balance. When the lift is stationary the spring balance reads W. If the lift suddenly falls freely under gravity the reading on the spring balance will be :

115) Two equal masses of mass M are attached to two ends of a string passing over a smooth pully attached to the ceiling by a chain. The tension in the chain is :

116) A cricketer catches ball of mass 150 gm in 0.1 sec moving with speed 20 m / s , then the experiences force of :

117) 25 N force is required to raise 75 kg mass from a pully. If rope is pulled 12 m , then the load is lift to 3 m , the efficiency of pulley system will be :

118) A 5 kg stationary bomb is exploded in three parts having mass 1 : 1 : 3 respectively. Parts having same mass move in perpendicular directions with velocity 39 m /s , then the velocity of bigger part will be:

119) A gun fires a bullet of mass 50 gm with a velocity of 30 m / s . Because of this, the gun if pushed back with a velocity of 1 m / s . The mass of the gun is :

120) A golf ball of mass 0.05 kg placed on a tee, is struck by a golf club. The speed of the golf ball as it leaves the tee is 100 m / s , the time of contact between them is 0.02s . If the force decreases to zero lineraly with time, then the force at the beginning of the contact is :

121) Rocket engines lift it from earth surface because hot gas with high velocity :

122) A light string passes over a frictionless pulley has masses of 6 kg and 10 kg attached to the free ends. The tension in the thread is :

123) A block of weight 10 N is resting on a horizontal surface. The coefficient of static friction between the block and the surface is 0.4. A force of 3.5 N will keep the block in uniform motion once it is set in motion. What happens to the block when a horizontal force of 3.0 N acts on the block ?

124) A block of mass 10 kg is placed on rough horizontal surface whose coefficient of friction is 0.5 . If a horizontal force of 100 N is applied on it, then acceleration of block will be :

125) A body moving with a velocity of 10 m / s bursts into two parts A and B of masses 6 kg and 1 kg. If part A continues to move in the original direction, with 12.5 m/s , velocity of part B is :

126) The mass of a body measured by a physical balance in a lift at rest is found to be ' m ' . If the lift is going up with an acceleration of 'a ' , its mass will be indicated as:

127) If rope of lift breaks suddenly. The tension exerted by the surface of lift is ( a = Acceleration of lift ) :

128) A bird weighing 1 kg is sitting on the base of cage weighing 1.5 kg . The bird starts flying inside the cage the weights of the bird cage assembly will now be :

129) A body of mass m collides against a wall with the velocity v and rebounds with the same speed. Its change of momentum is :

130) In case of uniform circular motion which of the following physical quantity does not remain constant :

131) In the motion of rocket, physical quantity which is conserved is :

132) Physical independence of force is a consequence of :

133) Two forces 12 N and 8 N act on a body of mass 24 kg. Whatever may be the directions of the forces, the acceleration of the body cannot be less than :

134) A book is lying on the table. What is the angle between the action of the book on the table and the reaction of the table on the book ?

135) A man of mass 60 kg is standing on a spring balance inside a lift. If the lift falls freely downwards, then the reading of the spring balance would be :

136) Sand is being dropped on a conveyor belt at the rate of M Kg /s . The force necessary necessary to keep the belt moving with a constant velocity of v m / s will be :

137) The mass of a lift is 2000 kg . When the tension in the supporting cable is 28000 N, then acceleration is :

138) A body of mass m hits normally a rigid wall with velocity V and bounces back with the same velocity. The impulse experienced by the body is :