A thin prism in air produces the angle of minimum deviation . If the prism is immersed in water, the angle of minimum deviation for the same ray is (refractive index of water is 4/3 and that of glass prism is 3/2 )

Step-by-step solution

The deviation produced by a thin prism in air is given by = ( _g - 1)A . Substituting _g = 3 2 , we get = ( 3 2 - 1 )A = A 2 . When the prism is immersed in water, the relative refractive index of glass with respect to water is _ gw = _g _w = 3/2 4/3 = 9 8 . The new angle of minimum deviation is ' = ( _ gw - 1)A . Substituting _ gw = 9 8 , we get ' = ( 9 8 - 1 )A = A 8 . Comparing the two deviations, ' = A/8 A/2 = 1 4 . Thus, ' = 4 . Answer: 4