Question

The radius of curvature of a concave mirror is 40 cm find position of the real image of an object in front of the mirror so that its magnification is -2

Answer 1

Explanation:

R= -40 cm

40 cmso, f= -20 cm

20 cm m= -2 . so, -v/u = -2

v = 2u _____ (i)

By mirror formula ,

1/f =(1/v) + (1/u)

1/-20 = 1/2u + 1/u

1/-20 = 1/u (3/2)

u= -30 cm

• now ;

v = 2 × u

= 2 × -30 cm

= - 60 cm

ANSWER :: - 60cm