Cls 10 Sci Chp 10. Solsn

Class 10 Science Solutions 

Chapter 10 Light - Reflection and Refraction

Page: 168

1. Define the principal focus of a concave mirror.

Ans:

Light rays that are parallel to the principal axis of a concave mirror converge at a specific point on its principal axis after reflecting from the mirror. This point is called the principal focus of the concave mirror.

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

Ans:

Radius of curvature (R) = 20 cm

Radius of curvature of the spherical mirror = 2 × Focal length (f)

R = 2f

f= R/2 = 20 / 2 = 10

Therefore, the focal length of the spherical mirror is 10 cm.

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

Ans: Concave Mirror.

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

Ans:

Convex mirrors always form an erect, virtual, and diminished image of the objects placed in front of it.

Page No: 171

1. Find the focal length of a convex mirror whose radius of curvature is 32 cm.

Ans:

Radius of curvature (R) = 32 cm

Radius of curvature = 2 × Focal length (f)

R= 2f

f = R/2 = 32/2 = 16

Therefore, the focal length of the given convex mirror is 16 cm.

2. concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located ?

Ans:

Because the image is real, so magnification m must be negative.

Thus the image is located at a distance of 30 cm from the mirror on the object side of the mirror.