Question

Two identical objects are placed in front of convex mirror and concave mirror having same radii of curvature of 12 cm, at same distance of 18 cm from the respective mirrors. The ratio of sizes of the images formed by convex mirror and by concave mirror is :

(1) \(\frac{1}{2}\)

(2) 2

(3) 3

(4) \(\frac {1}{3}\)

Answer 1

Correct option is : (1) \(\frac{1}{2}\) 

 

Using \(m = \frac{f}{u-f}\)

\(m_1 = \frac{6}{18-6} = \frac{1}{2}\)

\(m_2 = \frac{6}{18+6} = \frac{1}{4}\)