Practice Test


Q1) When a ray of monochromatic light is incident normally on glass surface then refracted ray Show Answer


Q2) In periscopes, totally reflecting prisms are used which turns the ray through Show Answer


Q3) When a light is incident at one end of the fibre at a small angle, then refracted light falls on the wall of the fibre at an angle Show Answer


Q4) When a monochromatic ray of light travels from an optically denser medium to optically rarer medium then critical angle is the angle of incidence for which angle of refraction is Show Answer


Q5) The refractivity of the material of the prism is given by Show Answer


Q6) To observe any rainbow the altitude of sun or the angle made by the sun with the horizontal should be Show Answer


Q7) Angular width of primary rainbow is Show Answer


Q8) The average angle of inclination of the primary rainbow with the axis is Show Answer


Q9) The average angle of inclination of the secondary rainbow with the axis is Show Answer


Q10) A yellow light travels from rarer medium to denser medium. At the value of critical angle, the ray will Show Answer


Q11) The distance travelled by a ray of light in two media, in the same time are in the ratio 2:3. The ratio of refractive index of the first medium to second medium is Show Answer


Q12) The refractive index of air with respect to glass is 2/3. The refractive index of diamond with respect to air is 12/5. Then, the refraction index of glass with respect to diamond will be Show Answer


Q13) Light consists of Show Answer


Q14) If medium changes Show Answer


Q15) The colour of light is determined by Show Answer


Q16) LASER is a Show Answer


Q17) A wave of light of ___ wave length is called monochromatic light. Show Answer


Q18) When a ray of monochromatic light is incident obliquely on the interface of two media, Show Answer


Q19) When a monochromatic light passes from one transparent medium into another, its direction changes ( except for normal incidence). This phenomenon is known as Show Answer


Q20) The angle made by the incident ray with the reflecting surface or interface is called as Show Answer


Q21) The relation between angle of incidence and angle of refraction was discovered by Show Answer


Q22) The absolute refractive index of any medium is always Show Answer


Q23) When a ray of monochromatic light enters from rarer medium to denser medium obliquely, the angle of incidence i and angle of refraction r is related as Show Answer


Q24) The value of refractive index of ________ is highest. Show Answer


Q25) The velocity of light is different in different media. This is the cause of refraction according to Show Answer


Q26) The velocity of light is maximum in Show Answer


Q27) If the ray of light travels from medium 1 to medium 2 and ultimately reverses its path then the phenomenon is Show Answer


Q28) The bottom of a swimming pool appears to be less deep than actual because of Show Answer


Q29) When light travels from one medium to another, which are separated by sharp boundary, the quantity which does NOT change is Show Answer


Q30) The ray of light travelling from an optically denser medium to optically rarer medium bends Show Answer


Q31) Which of the following is NOT a property of light ? Show Answer


Q32) 'Mirage' is a phenomenon due to Show Answer


Q33) Brilliance of diamond is due to Show Answer


Q34) Which of the following is a CORRECT statement ? Show Answer


Q35) As ' i ' increases, intensity of Show Answer


Q36) Critical angle of light passing from glass to air is minimum for Show Answer


Q37) The angle of incidence corresponding to which angle of refraction is a right angle is called as Show Answer


Q38) An endoscope is used by a physician to view the internal parts of a body organ. It is based on the principle of Show Answer


Q39) The separation of white light into its constituent colours after passing through a prism is called as ______ of light. Show Answer


Q40) In telecommunications ___________ is used to carry sound signals coded in light signals, over large distance. Show Answer


Q41) The light entering into the fibre suffers Show Answer


Q42) The optical fibre acts as a Show Answer


Q43) Optical fibre consists of large number of Show Answer


Q44) When white light passes through prism then constituent colours are obtained because Show Answer


Q45) When white light passes through prism, the angle of deviation is Show Answer


Q46) As the refractive index of the material of prism for different colours increases their corresponding wavelengths Show Answer


Q47) A prism splits a beam of white light into its constituent colours. This is so because Show Answer


Q48) A ______ shaped triangular transparent block having three rectangular planes and two traingular planes is called a prism. Show Answer


Q49) The angle between the two planes rectangular refracting surface is called Show Answer


Q50) The rectangular face opposite to the refracting edge is called Show Answer


Q51) The angle between incident ray and ______ ray is called angle of deviation. Show Answer


Q52) A prism is placed in water. The angle of minimum deviation Show Answer


Q53) While deriving prism formula, angle of deviation is minimum if Show Answer


Q54) Thin prism has small Show Answer


Q55) A glass prism placed in a homogenous transparent medium will deviate an incident ray Show Answer


Q56) Angular dispersion depends upon Show Answer


Q57) The refractive index of the prism for violet colour is 1.7 and that for red is 1.65. Then dispersive power of the material of prism is Show Answer


Q58) Dispersive power of prism depends on Show Answer


Q59) A beam of light compose 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


Q60) A narrow beam of white light passes through glass slab having parallel faces. Then, Show Answer


Q61) When a glass prism is placed inside water, its dispersive power Show Answer


Q62) In optical instruments, to minimise the effect of dispersion and obtain clear and well defined images, Show Answer


Q63) The arrangement of dispersion without deviation is used in Show Answer


Q64) The complete circle of rainbow can be seen when Show Answer


Q65) The rainbow is formed due to Show Answer


Q66) The primary rainbow is due to _______ total internal reflection inside droplet and two refractions. Show Answer


Q67) The secondary rainbow is due to ________ total internal reflection inside droplet. Show Answer


Q68) In case of secondary rainbow, ______ colour is at the top. Show Answer


Q69) The straight line joining the sun and the observer along which centre of both the primary and secondary rainbow lies is called Show Answer


Q70) The first explanation of rainbow was given by Show Answer


Q71) One cannot see through fog, because Show Answer


Q72) The intensity of scattered light, according to Rayleigh's law is Show Answer


Q73) Rayleigh's law of scattering assumes Show Answer


Q74) The sky will appear red instead of blue if Show Answer


Q75) Beyond earth's atmosphere, the sky will look Show Answer


Q76) The sky appears blue because Show Answer


Q77) Just after the sunrise, the sun is very close to horizon, so the sunlight has to travel Show Answer


Q78) The sun appears reddish or orange reddish at the Show Answer


Q79) Our eyes are more sensitive to blue as compared to Show Answer


Q80) The angle between incident ray and reflected ray or refracted ray is called Show Answer


Q81) Blue colour of sky is due to phenomenon of Show Answer


Q82) Just after the sunrise, the sky appears reddish because Show Answer


Q83) When a ray of light passes from air to denser medium, its speed is reduced by 30%. What is the refractive index of the medium ? Show Answer


Q84) An object immersed in a fluid becomes invisible, if it Show Answer


Q85) Sir C.V. Raman was awarded nobel prize for his work concerned with which of the following phenomenon of radiation ? Show Answer


Q86) A person swimming at the bottom of swimming pool looks upto the diving board. The board Show Answer


Q87) Which of the following is the CORRECT statement. Show Answer


Q88) For visible light the wave length ranges from Show Answer


Q89) Dispersion of light is shown in the following diagram, select the CORRECT one. Show Answer


Q90) The principle used in optical fibre is Show Answer


Q91) The net angular dispersion without deviation is equal to Show Answer