Question

When a spherical mirror held towards the sun its sharp image is formed on a piece of carbon paper for same time, a hole is burnt in the carbon paper.

• A. What is the nature of spherical mirror ?
• B. Why is a hole burnt in the carbon paper ?
• C. At which point of the spherical mirror the carbon paper is placed ?
• D. What name is given to the distance between spherical mirror and carbon paper ?
• E. What Is the advantage of using a carbon paper rather than a whit paper ?

Answer 1

The correct option is A What is the nature of spherical mirror ?

A. The mirror used in this case is concave mirror which converges the parallel rays of light coming from the sun to a focal point of the mirror as shown above.

B . This happens because all the rays of light are focused one single point. A small point on the carbon paper absords all the heat by the rays and hence starts burning.

C. The carbon paper is kept at the focus in the focal plane of the mirror.

D. The name given to the distance is focal length.

E. The carbon paper absorbs more heat of the light rays than the white paper