(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Physics

If a light ray does not undergo, refraction at the boundary between two media, the angle of incidence is:

(a) A ray of monochromatic light enters glass PQRS as shown in the fig. Complete the path of ray till it emerges from the glass. (Critical angle of glass is 42⁰). 

(b) Draw diagram of a prism periscope.
(c) What are the advantages of total internal reflecting prism over plane mirror?

Make the correct choices for each of the following : 

Total Internal reflection takes place when 

(where ∠i = angle of incidence,  ∠r = angle of refraction, ∠C = critical angle)

In the following figure, show two rays A and B travelling from water to air. If the critical angle for water- air surface is 48°, complete the ray diagram showing the refracted rays for each. State conditions when the ray will suffer total internal reflection.

A lens forms the image of an object placed at a distance 15 cm from it, at a distance 60 cm in front of it. Find the focal length.

A convex lens forms an inverted image of size same as that of the object which is placed at a distance 60 cm in front of the lens. Find:

1. The position of the image, and
2. The focal length of the lens.

A concave lens forms an erect image of `1/3`^rd the size of the object which is placed at a distance 30 cm in front of the lens. Find:

1. the position of image, and
2. the focal length of the lens.

The focal length of a convex lens is 25 cm. Express its power with sign.

The power of a lens is -2.0 D. Find its focal length and its kind.

Describe how you would determine the focal length of a converging lens, using a plane mirror and one pin. Draw a ray diagram to illustrate your answer.

The bells of a temple are big in size. Why?