Rays from Sun converge at a point `15 cm` in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object ?

Options

A. 15 cm in front of the mirror
B. 30 cm in front of the mirror
C. between 15 cm and 30 cm in front of the mirror
D. more than 30 cm in front of the mirror

Answer

B

Explanation

The rays from sun i.e., from infinity, are parallel to principal axis after reflection converge at a point, known as focus. Therefore, focal length (F) of concave mirror is 15 cm. And we known that, same size, real and inverted image is formed by concave mirror when object is placed at focus 2 F or centre of curvature so to form same size image object will be placed at `15xx2=30` cm.