When a ray of light falls on a given plate at an angle of incidence \(60^{\circ}\), the reflected and refracted rays are found to be normal to each other. The refractive index of the material of the plate is:
1. | \(\frac{\sqrt{3}}{2} \) | 2. | \(1.5 \) |
3. | \(1.732 \) | 4. | \( 2\) |
A medium shows relation between i and r as shown. If the speed of light in the medium is nc then the value of n is:
1. 1.5
2. 2
3. 2–1
4. 3–1/2
In the figure shown the angle made by the light ray with the normal in the medium of refractive index is:
1. \(30^{\circ}\)
2. \(60^{\circ}\)
3. \(90^{\circ}\)
4. None of these
An air bubble in a glass slab with refractive index 1.5 (near-normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is:
1. | 8 | 2. | 10 |
3. | 12 | 4. | 16 |
A plane mirror is placed at the bottom of a fish tank filled with water of refractive index . The fish is at a height 10 cm above the plane mirror. An observer O is vertically above the fish outside water. The apparent distance between the fish and its image is:
1. 15 cm
2. 30 cm
3. 35 cm
4. 45 cm
Two slabs P & Q of transparent materials have a thickness in the ratio 2 : 5. If a ray of light takes the same amount of time to move from A to B and B to C, then the refractive index of Q with respect to P will be:
1. 0.4
2. 2.5
3. 1.4
4. 1.85