Practice Test

Q1) The dispersive power of the material of prism is given by Show Answer

Q2) A white ray of light is passing through a parallel glass slab. The emergent ray Show Answer

Q3) We use flint glass prism to disperse polychromatic light because lights of different colours Show Answer

Q4) Dispersive power depends upon Show Answer

Q5) A prism CANNOT be used Show Answer

Q6) Refractive index is Show Answer

Q7) The dispersive power is maximum for the material Show Answer

Q8) Refractive index, frequency and deviation are maximum for Show Answer

Q9) Light is dispersed by a prism because Show Answer

Q10) White light is incident on thin-walled hollow glass prism. The emergent light is Show Answer

Q11) In deviation without dispersion, Show Answer

Q12) When a prism is placed in the position of minimum deviation, the ray of light within the prism Show Answer

Q13) In the position of minimum deviation, when a ray of yellow light passes through the prism, then its angle of incidence is Show Answer

Q14) If the refractive indices of a prism for red, yellow and violet colours be 1.61, 1.63 and 1.65 respectively, then the dispersive power of the prism will be Show Answer

Q15) A convex lens, a glass prism and a solid sphere all are made of the same glass. The dispersive power will be Show Answer

Q16) The angle of minimum deviation of a flint glass prism relative to crown, glass prism having the same angle of refraction for the same wavelength will be Show Answer

Q17) In a direct vision spectroscope, one uses a flint and a crown glass prism combination to get zero mean deviation but a finite dispersion. Which of the following is an acceptable diagrammatic representation ?
[ C = crown, F = flint, V = violet, R = red ] Show Answer

Q18) Which of the following diagrams shows correctly the dispersion of white light by a prism ? Show Answer

Q19) A ray of light passes through an equilateral prism such that the angle of incidence is equal to the angle of emergence and the latter is equal to 1 / 2 of the angle of prism. The angle of deviation is Show Answer

Q20) If the refractive indices of crown glass fro red, yellow and violet colours are 1.5140, 1.5270 and 1.5318 respectively and for flint glass these are 1.6434, 1.6499 and 1.6852 respectively,then the dispersive powers for crown and flint glasses are respectively Show Answer

Q21) The angle of deviation is the angle between Show Answer

Q22) Statement 1 : A beam of white light does not give a spectrum on passing through a hollow prism.
Statement 2 : Speed of light outside the prism is different from the speed of light inside the prism Show Answer

Q23) Statement 1 : If the angles of the base of the prism are equal, then in the position of minimum deviation, the refracted ray will pass parallel to the base of the prism.
Statement 2 : In the case of minimum deviation, the angle of incidence is equal to the angle of emergence Show Answer

Q24) The angle of incidence is Show Answer

Q25) What is the angular width of the spectrum Show Answer

Q26) What is the length of spectrum if it is focussed on a screen by a lens of focal length 100 cm ? Show Answer

Q27) Statement 1 : It is possible to eliminate dispersion by combining two prism of same refracting angles but of different materials.
Statement 2 : The angular dispersion depends on refractive index of the material of the prism. Show Answer

Q28) Statement 1 : Dispersion of light occurs between velocity of light in a material depends upon its colour.
Statement 2 : The dispersive power depends only upon the material of the prism, not upon the refracting angle of the prism
Show Answer

Q29) An experiment was performed based on the above theory with red, green and blue light. Their refractive indices in the material were 1.39, 1.44 and 1.47 respectively. Which colour would get separated ? Show Answer

Q30) If hypothetically the density of the material is increased gradually, then which of the colour gets separated next ? Show Answer

Q31) As the density of the material of the prism keeps on increasing, then which of the following statement holds good ? Show Answer

Q32) When white light passes through a glass prism, one gets spectrum on the other side of the prism. In the emergent beam, the ray which is deviating least is or Deviation by a prism is lowest for Show Answer

Q33) When white light passes through the achromatic combination of prisms, then what is observed Show Answer

Q34) A light ray is incident by grazing one of the face of a prism and after refraction ray does not emerge out, what should be the angle of prism while critical angle is C Show Answer

Q35) Which of the following element was discovered by study of Fraunhofer lines Show Answer

Q36) By placing the prism in minimum deviation position, images of the spectrum Show Answer

Q37) When a white light passes through a hollow prism, then Show Answer

Q38) In dispersion without deviation Show Answer

Q39) For a material, the refractive indices for red, violet and yellow colour light are respectively 1.52, 1.64 and 1.60. The dispersive power of the material is Show Answer

Q40) A medium is said to be dispersive, if Show Answer

Q41) Dispersion can take place for Show Answer

Q42) A ray of light passes through an equilateral glass prism in such a manner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to 3/4 of the angle of the prism. The angle of deviation is Show Answer

Q43) Angle of prism is A and its one surface is silvered. Light rays falling at an angle of incidence 2A on first surface return back through the same path after suffering reflection at second silvered surface. Refractive index of the material of prism is Show Answer

Q44) Line spectrum contains information about Show Answer

Q45) Missing lines in a continuous spectrum reveal Show Answer

Q46) The refractive index of flint glass for blue F line is 1.6333 and red C line is 1.6161. If the refractive index for yellow D line is 1.622, the dispersive power of the glass is Show Answer

Q47) The wavelength of emission line spectrum and absorption line spectrum of a substance are related as Show Answer

Q48) The splitting of white light into several colours on passing through a glass prism is due to Show Answer

Q49) Dark lines on solar spectrum are due to Show Answer

Q50) Line spectra are due to Show Answer

Q51) The path of a refracted ray of light in a prism is parallel to the base of the prism only when the Show Answer

Q52) For a medium, refractive indices for violet, red and yellow are 1.62, 1.52 and 1.55 respectively, then dispersive power of medium will be Show Answer

Q53) If refractive index of red, violet and yellow lights are 1.42, 1.62 and 1.50 respectively for a medium. Its dispersive power will be Show Answer

Q54) Fraunhofer spectrum is a Show Answer

Q55) Colour of the sky is blue due to Show Answer

Q56) Which of the following spectrum have all the frequencies from high to low frequency range Show Answer

Q57) Which of the following colours suffers maximum deviation in a prism? Show Answer

Q58) The refractive index of the material of the prism for violet colour is 1.69 and that for red is 1.65. If the refractive index for mean colour is 1.66, the dispersive power of the material of the prism Show Answer

Q59) Dispersion of light is due to Show Answer

Q60) When white light enters a prism, it gets split into its constituent colours. This is due to Show Answer

Q61) The dispersive powers of crown and flint glasses are 0.02 and 0.04 respectively. In an achromatic combination of lenses the focal length of flint glass lens is 40 cm. The focal length of crown glass lens will be Show Answer

Q62) When a ray of light is incident normally on one refracting surface of an equilateral prism (Refractive index of the material of the prism = 1.5 Show Answer

Q63) Consider the following two statements A and B and identify the correct choice in the given answers:
A : Line spectra is due to atoms in gaseous state,
B : Band spectra is due to molecules Show Answer

Q64) The nature of sun's spectrum is Show Answer

Q65) For a prism of refractive index 1.732, the angle of minimum deviation is equal to the angle of the prism. The angle of the prism is Show Answer

Q66) The spectrum obtained from an electric lamp or red hot heater is Show Answer

Q67) Which one of the following alternative is FALSE for a prism placed in a position of minimum deviation Show Answer

Q68) The solar spectrum during a complete solar eclipse is Show Answer

Q69) Why sun has elliptical shape on the time when rising and sun setting? It is due to Show Answer

Q70) In the formation of a rainbow light from the sun on water droplets undergoes Show Answer

Q71) The Cauchy's dispersion formula is Show Answer

Q72) A convex lens, a glass slab, a glass prism and a solid sphere all are made of the same glass, the dispersive power will be Show Answer

Q73) A parallel beam of white light falls on a convex lens. Images of blue, yellow and red light are formed on other side of the lens at a distance of 0.20 m, 0.205 m and 0.214 m respectively. The dispersive power of the material of the lens will be Show Answer

Q74) The refractive index of a particular material is 1.67 for blue light, 1.65 for yellow light and 1.63 for red light. The dispersive power of the material is Show Answer

Q75) A beam of light composed of red and green ray is incident obliquely at a point on the face of rectangular glass slab. When coming out on the opposite parallel face, the red and green ray emerge from Show Answer

Q76) White light is passed through a prism ........... colour shows minimum deviation Show Answer