CP Practice Chapter 15

Refraction

1.A light beam shown below makes an angle of 20 with the normal shown in the linseed oil. Determine the angles  and ‘. (n for linseed oil is 1.48)

air

20linseed oil

‘water

2.Three sheets of plastic have unknown indices of refraction. Sheet 1 is placed on top of sheet 2, and a laser beam is directed onto the sheets from above so that the beam strikes the interface at an angle of 26.5 with respect to the normal. The refracted beam in sheet 2 is at 31.7 with respect to the normal. The experiment is repeated with sheet 3 on top of sheet 2, and with the same angle of incidence. The refracted beam makes an angle of 36.7 with the normal. The experiment is repeated again with sheet 1 on top of sheet 3, if the angle of incidence is the same, what is the expected angle of refraction?

3.A submarine if 300 m horizontally out from the shore and 100 m beneath the surface of the water. A laser beam is sent from the sub such that it strikes the surface of the water at a point 210 m from the shore. If the beam just strikes the top of a building standing directly at the waters edge, find the height of the building.

4.A light ray strikes a flat block of glass (n = 1.50) of thickness 2 cm at an angle of 30 as shown below. Trace the light beam through the glass and find the angles of incidence and refraction at each surface. 30

2 cm

d

5.When light passes through a prism as shown above, the beam gets shifted a distance, d. Find d.

  1. How long does the light take to travel through the glass piece?
  2. A ray of light travels from air into a liquid. The ray is incident upon the liquid at 30 degrees and refracts at 22 degrees. What is the liquid?
  1. A thick sheet of plastic, n = 1.5, is used as the side of an aquarium tank. Light reflected from a fish in the water has an angle of incidence of 35 degrees. At what angle does light enter the air?
  1. A light source, S, is located 2.0-m below the surface of a swimming pool and 1.5-m from one edge of the pool. The pool is filled with water.

A)At what angle does the light reaching the edge of the pool leave the water?

B)Does this cause the fish to appear shallower or deeper than it really is?

  1. A ray of light is incident upon a equilateral prism of n = 1.5.

A)Determine the angle of refraction?

B)Determine the angles A, B, C, and D?

A B

45 D

C

  1. A ray of light in a tank of water has an angle of incidence of 55 degrees. What is the angle of fraction in air?
  1. The critical angle for special glass in air is 41 degrees. What is the critical angle if the glass is immersed in water?
  1. A light bulb is under water 4.5-m, what area on the surface of the water can the bulb be seen by someone on a boat floating on top of the water?
  1. A) What is the critical angle of crown glass?

B)What is the speed of light in crown glass?