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

 

Answer.

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 .

convex-lens-object-at-infinity---ray-diagram---teachoo.jpg

concave-mirror---object-at-infinity---ray-diagaram---teachoo.jpg

So, the correct answer is (a)

  1. Class 10
  2. Chapter 10 Class 10 - Light - Reflection and Refraction (Term 1)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo