Physics

1A ray of light in air strikes glass at an angle of incidence of 30° and is refracted at 28°. Find the refractive index of the glass, to 2 decimal places.

2A coin lies at the bottom of a tank of liquid 4 m deep. If the refractive index of the liquid is 1.33, find the apparent depth, to 2 decimal places.

3Optical fibres work by

4The critical angle C is related to refractive index n by

5Light (speed 3 × 10⁸ m/s in vacuum) enters a medium of refractive index 1.6. Its speed in the medium is ___ × 10⁸ m/s.

6Prism binoculars use total internal reflection.

7Light (speed 3 × 10⁸ m/s in vacuum) enters a medium of refractive index 1.5. Its speed in the medium is ___ × 10⁸ m/s.

8A ray travelling along the normal is not bent.

9Light (speed 3 × 10⁸ m/s in vacuum) enters a medium of refractive index 1.2. Its speed in the medium is ___ × 10⁸ m/s.

10Diamond sparkles because of its small critical angle.