When an object is placed at a distance of 25 cm from a mirror, the magnification is m1. The object is moved 15 cm further away from mirror with respect to the earlier position and the magnification becomes m2. If m1/m2 = 4 , then calculate the focal length of the mirror :

A square of side 2 cm is placed at a distance of 30 cm from a concave mirror of focal length 20 cm. The centre of the square is at the axis of the mirror and the plane is perpendicular to the axis. The area enclosed by the image is :

A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that the end closer to the pole is 20 cm away from it. Find the length of the image :

A U-shaped wire is placed before a concave mirror having focal length 10 cm. Find the total length of the image :

An object O is placed in front of a plane mirror and concave mirror as shown in fig. If ‘f’ is the focal length of concave mirror then the separation between the two mirrors so that the images formed by mirrors coincide:

In the figure shown find the total magnification after two successive reflections first on M1 & then on M2 (Take Ist reflection from concave mirror)