Question

a concave mirror produces three times enlarged real image of an object placed at 12cm in front of it. calculate the radius of curvature of the mirror

Answer 1

Here,

Object distance, u = -12 cm

Let height of object be h, so height of image is -3h.

Magnification is,

m = -v/u = (-3h/h)

=> v = 3u

=> v = -36 cm

Now, 1/f = 1/v + 1/u

=> 1/f = -1/36 – 1/12

=> f = -9 cm

=> R = 2f = -18 cm

Thus, the radius of curvature is 18 cm.