Question

a candle is kept at a distance of 60 cm from a convex lens of focal length 20cm its image forms at a curtain kept on other side of the lens what is the distance between the length and the curtain​

Answer 1

Explanation:

u =-60

f =20

since ,

1/v -1/u =1/f

→v =fu/(f+u)

→v=20(-60)/(-60+20)

=-1200/-40=30

Hence required distance =30cm