Define the principal focus of a concave mirror.

 

Answer

The point at which 

rays parallel to principal axis

coming from infinity converge 

after being reflected from concave mirror 

is called the principal focus of concave mirror.

Concave Mirror - Object at Infinity - Teachoo.jpg

For a convex mirror

The point at which 

rays parallel to principal axis

coming from infinity appear to converge 

after being reflected from convex mirror 

is called the principal focus of convex mirror.

Convex Mirror - Object at Infinity - Teachoo.jpg

  1. Class 10
  2. Chapter 10 Class 10 - Light - Reflection and Refraction

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.