A boy is 1.8 m tall and can see his image in a plane mirror fixed on a wall. His eyes are 1.6 m from the floor level. The minimum length of the mirror required to view his complete image is :

A ray of light strikes a silvered surface inclined to another one at an angle of 90° then the reflected ray will turn through :

Two plane mirrors are inclined at an angle of 75° to each other. Find the total number of images formed when an object is placed as shown in figure.

Find the velocity of the image with respect to ground of a moving object in situation as shown in figure :

By what angle mirror should be rotated to obtain reflected ray on +y-axis :

An object is placed in front of a convex mirror of radius of curvature 20 cm. Its image is formed 8 cm behind the mirror. The object distance is :

When an object is kept at a distance of 30 cm from a concave mirror, the real image is formed at a distance of 10 cm. If the object is moved with a speed of 9 m/s along principal axis, the speed with which image moves is :

A person looks into a shaving mirror. The size of image of his face is twice the actual size of his face. If the face is at a distance 20 cm then find the radius of curvature of the mirror :

An object of length 2.5 cm is placed at a distance of 1.5f from a concave mirror of focal length f. The length of the object is perpendicular to the principal axis. Find the length of image ?

A light ray traveling parallel to the principal axis of a concave mirror strikes the mirror at angle of incidence q. If radius of curvature of the mirror is R, then after reflection, the ray meets the principal axis at distance d from the centre of curvature, then d is