Question

All lights are switched off, except for a bright
point-light source kept at the bottom of a swimming
pool filled with clear water of refractive index 4/3. As
a result, only a circular patch of 6 m diameter of the
water surface is visible to spectators standing around
the swimming pool. Which of the following gives the
nearest value of the depth of the pool?
a) 1.6m b) 2.0m
c) 2.6m d) 3.0m​

Answer 1

so answer is 2.6 we should consider phenomenon of total internal reflection