Chapter 10: Reflection and Refraction- Exercise- 1

Science

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Chapter 10: Reflection and Refraction

Class: X

Exercise: 1

 

Question 1

Define the principal focus of a concave mirror.

Answer 1

The principal focus of a concave mirror is point at which light incident towards the mirror and traveling parallel to the principal axis meet after reflection from the mirror.

Question 2

The radius of curvature of a spherical mirror is 20 cm. What is its focal length?

Answer 2

Radius of curvature of a spherical mirror, R = 20 cm

Hence, the focal length of the given spherical mirror is 10 cm. 

Question 3

Name the mirror that can give an erect and enlarged image of an object.

Answer 3

Concave mirror. The image formed is virtual, erect, and enlarged when an object is placed between the pole and the principal focus of a concave mirror.

Question 4

Why do we prefer a convex mirror as a rear-view mirror in vehicles?

 

Answer 4

We prefer a convex mirror as a rear-view mirror in vehicles because a highly-diminished image is formed thus making the traffic look much smaller. As a result, we can see a large number of vehicles in a very small mirror.