Refraction Worksheet
For each question remember to draw a diagram and show all of your working, including the equation you are using.
1. A ray of light is incident in glass on a glass-water boundary. The angle of incidence is 50˚. Calculate the angle
of refraction. (Refractive index of glass = 1.50, refractive index of water = 1.33)
2. A ray of light is incident in air on the surface of a glass block. The angle of incidence is 60˚. Calculate the
angle of refraction. (Refractive index of glass with respect to air = 1.50.)
3. A ray of light is incident in water: a) on a plane water-air boundary at an angle of incidence 45˚, b) on a plane
water-glass boundary at an angle of incidence of 30˚. Calculate the angle of refraction in each case.
(Refractive index glass = 1.50, refractive index water = 1.33.)
4.
A ray of light in incident in glass on a plane glass-air boundary and makes an angle of 30˚ with the normal to
the boundary. Calculate the angle through which the ray is deviated on entering the air. (Refractive index of
glass with respect to air = 1.5.)
5. A ray of light travelling through a liquid of
absolute refractive index 1.4 is incident on the
plane surface of a perspex block at an angle of
55˚. Calculate the angle of refraction in the
perspex if it has an absolute refractive index
of 1.5.
Air
n = 1.00
Glass
n = 1.52
y
x
50.0˚
6. In the diagram a ray of light travelling through
air is incident at A at an angle of 50.0˚ on to a
glass surface which is coated with a layer of
liquid. Use the information given in the table
to find the angles x and y.
Liquid
n = 1.35
A
Absolute refractive index of liquid
Absolute refractive index of glass
Assume parallel
layers
1.35
1.52
7. A ray of light travelling through air is incident at an angle of 30.0˚ on to the first face of a perspex prism of
angle 45.0˚. If the Perspex has refractive index 1.49, calculate the angle of the emergence at the second face.
30.0˚
45.0˚