CBSE
The radius of the convex surface of the plano-convex lens is 20 cm and the refractive index of the material of the lens is 1.5. The focal length is :
30 cm
50 cm
20 cm
40 cm
The deviation is maximum for which colour :
Violet
Red
Blue
Green
A person who can see things most clearly at a distance of 10 cm, requires spectacles to enable to see clearly things at a distance of 30 cm. What should be the focal length of the spectacles?
15 cm (concave)
15 cm (convex)
10 cm (concave)
0
A transparent cube of 15 cm edge contains a small air bubble. Its apparent depth, when viewed through one face, is 6 cm and when viewed through the opposite face is 4 cm. Then the refractive index of the material of the cube is:
2.0
2.5
1.6
1.5
If the critical angle for total internal reflection from a medium to vacuum is 30°, the velocity of light in the medium is :
3 × 108 m/s
1.5 × 108 m/s
6 × 108 m/s
× 108 m/s
For a telescope, larger be the diameter of the objective lens:
greater the resolving power
smaller is the resolving power
greater is the magnifying power
smaller is the magnifying power
The refractive index of the material of the prism and liquid are 1.56 and 1.32 respectively. What will be the value of θ for the following refraction?
A prism of refractive index √2 has a refracting angle of 60°. At what angle a ray must be incident on it so that it suffers a minimum deviation?
45°
60°
90°
180°
A light wave travels from glass to water. The refractive indices for glass and water are and respectively. The value of the critical angle will be :
In the given figure, what is the angle of the prism?
A
B
C
D