Question

Fill in the following blanks with suitable words :

(a) Parallel rays of light are reflected by a concave mirror to a point called the ___.

(b) The focal length of a concave mirror is the distance from the ___ to the mirror.

(c) A concave mirror ___rays of light whereas a convex mirror___rays of light.

(d) For a convex mirror, parallel rays of light appear to diverge from a point called the___.

Answer 1

(a)

1. The light rays parallel to each other are converged at a point after reflection from a concave mirror.
2. The point is termed as the focus of the concave mirror.

Thus,

Parallel rays of light are reflected by a concave mirror to a point called the focus.

b)

1. The distance between the focus and the pole that is the midpoint of the mirror is called the focal length of the mirror.
2. It is denoted by f. ​

The focal length of a concave mirror is the distance from the focus to the mirror.

c)

1. As a concave mirror converges the light rays at its focus, therefore it is also known as a converging mirror.
2. ​A convex mirror diverges the light rays that are incident on it therefore a convex mirror is also known as a diverging mirror.

A concave mirror converges rays of light whereas a convex mirror diverges rays of light.

d)

1. A convex mirror is a diverging mirror.
2. All the light rays which are parallel to each other appear to diverge from a point of the convex mirror which is called the focus of the convex mirror.​

For a convex mirror, parallel rays of light appear to diverge from a point called the focus.

Thus, the correct word for the blanks are;

a) focus

b) focus

c) converges, diverges

d) focus