Question

The concave mirrors are used in

• A. reflecting telescopes
• B. magic-lanterns
• C. cinema projectors
• D. all of the above

Answer 1

The correct option is D

all of the above

Reflecting telescopes:

1. A concave mirror is called a 'converging mirror'.
2. It concentrates the rays of light from infinity at the focus
3. Thus, they are widely used in telescopes for viewing objects at infinity.

Magic-lanterns:

Being a converging mirror, a concave mirror is used to direct and focus light through the lens creating a brighter projection picture.

Cinema projectors:

Concave mirrors are used to obtain a real inverted image of the object at focus.

Hence, option D is the correct answer.