Question

The image of an object placed on the principal axis of a concave mirror of focal length 12 cm is formed at a point which is 10 cm more distant from the mirror than the object. The magnification of the image is –

• A. 8/3
• B. 2.5
• C. 2
• D. –1.5

Answer 1

Answer: (D)

–1.5

Answer 2

u = –x

+ = $\frac { - 1 } { 12 }$

on solving x = –6 or x = 20

so u = 6 or u = –20 cm

m = $\frac { - ( - 30 ) } { - 20 }$ = –1.5