Wave Theory of Light

1.When a ray of light enters a glass slab from air


a) its wavelength decreases
b) its wavelength increases
c) its frequency increases
d) none of the above


2.The linear distance between successive points that have same phase on any wave is called


a) amplitude
b) frequency
c) wavelength
d) period


3.Which of the following does not support the wave nature of light?


a) interference
b) diffraction
c) polarisation
d) photoelectric effect




5.Light appears to travel in a straight line since


a) it is not absorbed by the atmosphere
b) it is reflected by the atmosphere
c) its wave length is small
d) its velocity is very large

6.Which of the following phenomena is not common to sound and light waves


a) interference
b) diffraction
c) polarisation
d) reflection


7.A ray of light from air is incident on the surface of glass at polarising angle. It suffers a deviation of 22⁰on entering glass. The angle of polarisation is


a) 22⁰
b) 56⁰
c) 68⁰
d) 34⁰


8.The angle of polarisation of glass 58⁰ and that for water 53⁰. The angle of polarisation for glass from water is


a) tan^-158⁰/tan^-153⁰
b) tan58⁰/tan53⁰
c) tan^-1(tan58⁰/tan53⁰)
d) tan^-1(tan53⁰/tan58⁰)


9.Choose the correct statement


a) Brewsters angle is independent of the wavelength
b) Brewsters angle is independent of the material of the reflecting surface
c) Brewsters angle depends on wave length but not on the nature of the reflecting surface
d) Brewsters angle is different for different wave length


10.If light is completely polarised by reflection at a plane refracting surface then the angle between reflected and refracted light is


a)π
b) π/2
c) π/4
d) π/6


11.Polarisation of light proves

a) corpuscular nature of light
b) quantum nature of light
c) transverse nature of light
d) longitudinal nature of light

12.Suppose a glass slab of thickness ‘t’ and refractive index ‘n’ is placed on a printed page of a book you are reading. The prints will

a) appear to be shifted towards you by (t – t/n)
b) appear to be shifted towards you by t/n
c) appear to be shifted away from you by (t – t/n)
d) appear to be shifted away from you by t/n

13. At what angle with respect to the horizontal, does a fish under water see the setting sun?

a) tan–1(√7/3)
b) tan–1(5/3)
c) tan–1(5/√7)
d) tan–1(√5/3)

14.) A ray of light passing through a prism having µ=√2 suffers minimum deviation. If angle of incidence is double the angle of refraction within prism, the angle of prism is

a) 30⁰

b) 45⁰

c) 60⁰

d) 90⁰

15.White light is incident on the interface of glass and air as shown in the figure. If green light is just totally internally reflected, then the emerging ray in air contains

a) yellow, orange, red

b) violet, indigo, blue

c) all colours

d) all colours except green






                                           ANSWERS WILL BE POSTED ON 12/09/10