Question

a concave mirror of radius 30 cm is placed in water . its focal length in air and water differ by​

Answer 1

$\huge\underline\mathfrak\pink{\underline{Answer}}$

The focal length in air and water differ by 15 cm.

As we know that the focal length is half of the radius of curvature. Thus, the focal length in air and water differ by 15 cm

Answer 2

Answer:

answer is 0 degree....