Question

A scuba diver wears a diving mask with a faceplate that bulges outward with a radius of curvature of 0.25m. There is thus a convex spherical surface between the water, n=4/3, and the air in the mask. Neglect the glass itself. A fish is 2.5m in front of the mask. What is the magnification of the fish?

Answer 1

The diver is looking at the fish, so the light is going from the fish to the diver's eyes Thus the incident index is n_{​​​​​​i} = 4/3 and transmitted index is n_{​​​​​​t} = 1. The radius of curvature of the surface is positive, since the center of curvature is on the transmitted side. This is a single-surface refraction problem,

Where, s = 2.5 m , ni = 4/3 , nt = 1 , r = 0.25 m ,s' =?

So the fish appears to be on the incident of the mask.

Now, Magnification of the fish,

​​​​​​

M= + 0.29 _Ans.