In torches, search lights and headlights of vehicles the bulb is placed
(a) between the pole and the focus of the reflector
(b) very near to the focus of the reflector
(c) between the focus and centre of curvature of the reflector
(d) at the centre of curvature of the reflector
- A concave mirror is used in headlights of vehicles and torches.
- The mirror converges beams of light in one direction.
- Since we would want the beams to travel as far as possible so we can see in the distance , they should be parallel .
- A concave mirror produces parallel beams when the source of light is at the focus or very near to it.
So, the correct answer is (b)