Question

What is known as linear magnification of spherical mirrors?
(A) Ratio of size of image to size of object
(B) Ratio of shape of image to size of object
(C) Ratio of size of image to shape of object
(D) None

Answer 1

Hint: The linear magnification of a spherical mirror is the ratio of the image that is formed by the mirror to the size of the object that is placed in front of the mirror. It is denoted by the letter m.

Complete step-by-step answer:
A spherical mirror is a mirror of the shape of a part of a spherical surface that has been cut out. One of the surfaces of the mirror is polished so that the other face becomes reflective. When the inner surface is painted, then the mirror becomes a convex mirror. And if the outward surface is painted, then the mirror is called a concave mirror.
The concave mirrors are called converging mirrors as they converge the rays of light falling on the surface whereas, the convex mirrors diverge the rays of light.
The magnification of spherical mirrors means the increase in the size of the images formed by the mirrors with respect to the objects placed in front of them.
The magnification of a mirror is the ratio of the height of the image to the height of the object and is denoted by the letter $m$, where
$m = \dfrac{{h'}}{h}$ where $h'$ is the height of the image and $h$ is the height of the object.

So the correct answer will be option A. Ratio of size of image to size of object.

Note: The magnification of objects can also be calculated by the ratio of the distance of the image from the mirror to the distance of the object from the mirror. Therefore, it is written as,
$m = \dfrac{v}{u}$ where $v$ is the image distance and $u$ is the object distance.