Question

In torches, search lights and headlights of vehicles the bulb is placed ______.

Options

• between the pole and the focus of the reflector

• very near to the focus of the reflector

• between the focus and centre of curvature of the reflector

• at the centre of curvature of the reflector

Answer 1

In torches, search lights and headlights of vehicles the bulb is placed very near to the focus of the reflector.

Explanation - 

In torches, search lights and headlights of vehicles concave mirrors are used. When a light source is placed at the focus of the mirror, after reflection light rays become parallel to the principal axis. Due to this, the bulb is placed very near to the focus of the reflector.