Question

The focal length of a lens u = 1.5 in air is 20 cm. Its focal length in medium of
refractive index 1.5 is
(A) 20 cm
(B) 40 cm (C) 10 cm (D) 00​

Answer 1

Answer:

(B) 40 cm is the focal length of lens if refractive index is 1.5

Answer 2

Answer:

40cm focal length of this lens