Which of the following can make a parallel beam of light when light from a point source is incident on it?
(a) Concave mirror as well as convex lens
(b) Convex mirror as well as concave lens
(c) Two plane mirrors placed at 90° to each other
(d) Concave mirror as well as concave lens
Only converging lens and converging mirror can make a parallel beam of light incident on a point.
- Concave mirror is a converging mirror.
- Convex lenses converge to light rays, hence convex lenses are also called converging lenses .
So, the correct answer is (a)