Question

22.In an experiment an object was placed on the principal axis of a
convex lens 25 centimeters away from the lens. A real image 4
times the size of the object was obtained. The focal length of the
lens is
20 am
25 am
33 cm
E.
100 cm​

Answer 1

Answer:

20 cm

Explanation:

v/u=4

v=4u

by lens formula

1/4u+1/u=1/f

by solving

20cm