Question

The radius of curvature of a concave lens is 20 CM. Its focal length will be

(a) -20 cm

(b) -10 cm

(c)40 cm

(d)10 cm

Answer 1

_20 the radius of curvature of a concave lenns

so focal length will be 40

Answer 2

(d)10 cm is your final answer

Please mark this answer as brainliest