Question

A CONCAVE MIRROR IS HALF DIPPED IN WATER.FOCAL LENGTH OF PORTION OF MIRROR IS THE AIR IS f1 AND FOCAL LENGTH OF MIRROR IN WATER IS f2 ,THEN (REFRACTIVE INDEX OF WATER =4/3)

Answer 1

For spherical mirror if R is radius of curvature, then focal length f=R/2.

Now, R is geometrical factor and it remains the same in air and liquid. So, f does not change.

Answer 2

Answer:

f1 equal to f2

Explanation:

Missing options in question :-

1) f1 greater than f2

2) f2 greater than f1

3) f1 equal to f2

4) f1 greater than equal to 4/3 f2

5) f2 greater than equal to 4/3 f1

Answer :- f1 equal to f2

Since the focal length of the mirror does not depend on the medium in which it is held.