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 sunrise or sunset, the sun looks more red than at midday because Show Answer


Q6) A prism CANNOT be used Show Answer


Q7) Refractive index is Show Answer


Q8) The dispersive power is maximum for the material Show Answer


Q9) Refractive index, frequency and deviation are maximum for Show Answer


Q10) Light is dispersed by a prism because Show Answer


Q11) White light is incident on thin-walled hollow glass prism. The emergent light is Show Answer


Q12) In deviation without dispersion, Show Answer


Q13) When a prism is placed in the position of minimum deviation, the ray of light within the prism Show Answer


Q14) In the position of minimum deviation, when a ray of yellow light passes through the prism, then its angle of incidence is Show Answer


Q15) 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


Q16) A convex lens, a glass prism and a solid sphere all are made of the same glass. The dispersive power will be Show Answer


Q17) 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


Q18) 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


Q19) Which of the following diagrams shows correctly the dispersion of white light by a prism ? Show Answer


Q20) 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


Q21) 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


Q22) The angle of deviation is the angle between Show Answer


Q23) 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


Q24) 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


Q25) The angle of incidence is Show Answer


Q26) What is the angular width of the spectrum Show Answer


Q27) What is the length of spectrum if it is focussed on a screen by a lens of focal length 100 cm ? Show Answer


Q28) 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


Q29) 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


Q30) 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


Q31) If hypothetically the density of the material is increased gradually, then which of the colour gets separated next ? Show Answer


Q32) As the density of the material of the prism keeps on increasing, then which of the following statement holds good ? Show Answer


Q33) Which source is associated with a line emission spectrum Show Answer


Q34) 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


Q35) Fraunhofer lines are obtained in Show Answer


Q36) Light from sodium lamp is passed through cold sodium vapours, the spectrum of transmitted light consists of Show Answer


Q37) In the formation of primary rainbow, the sunlight rays emerge at minimum deviation from rain-drop after Show Answer


Q38) When white light passes through the achromatic combination of prisms, then what is observed Show Answer


Q39) The number of wavelengths in the visible spectrum Show Answer


Q40) The black lines in the solar spectrum during solar eclipse can be explained by Show Answer


Q41) 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


Q42) The spectrum of light emitted by a glowing solid is Show Answer


Q43) Which of the following element was discovered by study of Fraunhofer lines Show Answer


Q44) By placing the prism in minimum deviation position, images of the spectrum Show Answer


Q45) Our eye is most sensitive for which of the following wavelength Show Answer


Q46) The minimum temperature of a body at which it emits light is Show Answer


Q47) Band spectrum is obtained when the source emitting light is in the form of or Band spectrum is characteristic of Show Answer


Q48) A circular disc of which 2/3 part is coated with yellow and 1/3 part is with blue. It is rotated about its central axis with high velocity, then it will be seen as Show Answer


Q49) The fine powder of a coloured glass is seen as Show Answer


Q50) When a white light passes through a hollow prism, then Show Answer


Q51) In dispersion without deviation Show Answer


Q52) 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


Q53) Band spectrum is produced by Show Answer


Q54) The band spectra (characteristic of molecular species) is due to emission of radiation Show Answer


Q55) Line spectrum was first of all theoretically explained by Show Answer


Q56) The spectrum of iodine gas under white light will be Show Answer


Q57) Continuous spectrum is not due to Show Answer


Q58) Fraunhofer lines are produced by Show Answer


Q59) A medium is said to be dispersive, if Show Answer


Q60) Dispersion can take place for Show Answer


Q61) 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


Q62) The true statement is Show Answer


Q63) What will be the colour of sky as seen from the earth, if there were no atmosphere Show Answer


Q64) When light emitted by a white hot solid is passed through a sodium flame, the spectrum of the emergent light will show Show Answer


Q65) At the time of total solar eclipse, the spectrum of solar radiation would be Show Answer


Q66) 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


Q67) When seen in green light, the saffron and green portions of our National Flag will appear to be Show Answer


Q68) At sun rise or sunset, the sun looks more red than at mid-day because Show Answer


Q69) Line spectrum contains information about Show Answer


Q70) Missing lines in a continuous spectrum reveal Show Answer


Q71) A neon sign does not produce Show Answer


Q72) 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


Q73) The wavelength of emission line spectrum and absorption line spectrum of a substance are related as Show Answer


Q74) From which source a continuous emission spectrum and a line absorption spectrum are simultaneously obtained Show Answer


Q75) The splitting of white light into several colours on passing through a glass prism is due to Show Answer


Q76) A white screen illuminated by green and red light appears to be Show Answer


Q77) Dark lines on solar spectrum are due to Show Answer


Q78) Line spectra are due to Show Answer


Q79) The path of a refracted ray of light in a prism is parallel to the base of the prism only when the Show Answer


Q80) 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


Q81) 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


Q82) Fraunhofer spectrum is a Show Answer


Q83) Colour of the sky is blue due to Show Answer


Q84) Which of the following spectrum have all the frequencies from high to low frequency range Show Answer


Q85) Stars are not visible in the day time because Show Answer


Q86) Which of the following colours suffers maximum deviation in a prism? Show Answer


Q87) 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


Q88) Dispersion of light is due to Show Answer


Q89) Which of the prism is used to see infrared spectrum of light Show Answer


Q90) When white light enters a prism, it gets split into its constituent colours. This is due to Show Answer


Q91) 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


Q92) 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


Q93) 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


Q94) The nature of sun's spectrum is Show Answer


Q95) 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


Q96) The spectrum obtained from an electric lamp or red hot heater is Show Answer


Q97) Which one of the following alternative is FALSE for a prism placed in a position of minimum deviation Show Answer


Q98) The solar spectrum during a complete solar eclipse is Show Answer


Q99) Why sun has elliptical shape on the time when rising and sun setting? It is due to Show Answer


Q100) In the formation of a rainbow light from the sun on water droplets undergoes Show Answer


Q101) The Cauchy's dispersion formula is Show Answer


Q102) 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


Q103) 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


Q104) 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


Q105) 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


Q106) White light is passed through a prism ........... colour shows minimum deviation Show Answer