Question

(a) Write down formula for the magnification obtained by a spherical mirror.
(b) Name a mirror that can give an erect and enlarged image of an object.
(c) Define the principle focus of a convex mirror.

Answer 1

a)Magnification is the increase in the image size produced by spherical mirrors with respect to the object size. It is the ratio of the image height (h) to object height (h') and is denoted as;
Mirror formula is given by ,
$$m=\frac{h}{h^{\prime }}$$
Magnification is also given by ratio of image distance, $v$ (distance of the image from the pole of the mirror) to the object distance $u$ (distance of the object from the pole of the mirror).
$$m=\frac{v}{u}$$
b)When object is placed between focus and pole of concave mirror, it can give an erect and enlarged image.

c) Principle focus of a convex mirror is a point on its principle axis from which incident ray parallel to the axis after reflection, appears to diverge.