Question

The apparent depth of ater in water in cylindrical water tank of diameter `2R cm` is reducing at the rate of `x cm//min` when is being drined out a constant rate. The amount of water drained in `cc//min` is (`n_1=`refractive index of air, `n_2=`refractive index of water)
A. `(xpiR^2n_1)/n_2`
B. `(xpiR^2n_1)/n_1`
C. `(2piRn_1)/n_2`
D. `piR^2x`

Answer 1

Correct Answer - B
`d_(app)=d/((n_1//n_2))`
`:. d=n_2/n_1 d_(app)`
`-d/(dt) =n_2/n_1(-d/(dt) d_(app))=(n_2/n_1)x`
`(dv)/dt=A[-d/(dt)(d)]=(xpiR^2n_2)/n_1`