Optics (Physics) Rifraction and Total internal Rifraction

1. Advanced level Physics T.M.Ramanan,B.Sc (Hons) Physics
Exam-01
Optics (Physics)
Time: 1hour
1. Light of wavelength 590nm in vacuum passes through a piece of fused quartz of index of
refraction n=1.45
a. Find the speed of light in fused quartz.
b. What is the wavelength of this light in
fused quartz.
2. What is the angle 𝜃 such that the light rays
will be totally internally reflected assuming
that the pipe has an index of refraction of
npipe =1.30 and is surrounded on all sides by
air.
3. Calculate the critical angle for the boundary between glass (n = 1.50) and diamond (n =
2.42)
4. In an experiment, a light ray is incident on a semicircular glass block from air.
If r = 19.2 when i = 30. Find r if i = 60.
5. An incident ray in air (n=1.0) is approaching the boundary with an unknown material at
an angle of incidence of 60°. The angle of refraction is 45°. Determine the index of
refraction of the unknown material
6. A light ray enters a rectangular ice block of refractive index 1.31 from air
as shown. If the ray is totally reflected on surface AB, what is the
maximum value of angle ?
7. A ray of light passing through a prism having n= √2 suffers minimum deviation. If
Angle of incidence is double the angle of refraction within prism,find the angle of prism.
8. An observer looks at the water tank and according to him half of the tank is filled with
water. If the height of the tank is 180cm, find the real height of the water in the tank.
(nwater=4/3)
9. A tank filled with water to a height of 12.5cm. The apparent depth of a needle lying at
the bottom of the tank is measured by a microscope to be 9.4cm.
What is the refractive index of water?

A B
air
ice