The deviation produced by a thin glass prism placed in air, when immersed in water is
[Given `""_(a)mu_(g) = 3//2 and ""_(a)mu_(w) = 4//3`]

Explanation

`P_(w)=(mu_(w))/(f_(w))=mu_(w)[(mu_(g))/(mu_(w))-1]*[(1)/(R_(1))-(1)/(R_(2))]` …(i)
`P_("air")=(1)/(f_("air"))=[mu_(g)-1][(1)/(R_(1))-(1)/(R_(2))]` …(ii)
eqn. (i) div (ii), gives
`(P_(w))/(P_("air"))=((mu_(g)-mu_(w)))/((mu_(g)-1))`
`P_(w)=(((3)/(2)-(4)/(3)))/(((3)/(2)-1))xx5=(1//6)/(1//2)xx5`
`impliesP_(w)=(2)/(6)xx5=(10)/(6)=(5)/(3)` D.
The power of the lens gets altered inside water.