Question

What will be the height of image when an object of 2 mm is placed on the axis of a convex mirror at a distance 20 cm of radius of curvature 40 cm(a) 20 mm(b) 10 mm(c) 6 mm(d) 1 mm

Answer 1

answer : option (d) 1mm

explanation : height of object , h = 2mm

object distance, u = -20cm

radius of curvature of convex mirror, R = 40cm
so, focal length of convex mirror, f = 20cm

use formula, 1/v + 1/u = 1/f

or, 1/v + 1/-20 = 1/20

or, 1/v = 1/20 + 1/20 = 1/10

hence, v = 10cm

now, m = -v/u = -(10cm)/(-20cm) = 1/2 = height of image /height of object

height of image = 1/2 × 2mm = 1mm

Answer 2

Answer:

1mm

the right answer is 1mm