In the concave reflector of a torch, the bulb is placed :

Filament of a torch bulb is

The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch?

The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch?

Name the best reflector of light.

Write down the structure of a torch bulb.

Good reflector of sound:

A concave reflector of radius of curvature 110 cm is used by a reflecting type telescope. What will be the focal length of eyepiece required to obtain a magnification of 20?

What is reflector?