Question

Rohit focus image of a candle flame on a white screen using convex lens he noted down the position of candle, screen and lens as given.....
Position of candle = 26 cm. Position of convexlens =50cm
Position of screen = 74 cm . Find given above .............

Answer 1

As object is at C,
f=76-50/2=12 cm
(b) at infinity