A flint glass prism and a crown glass prism are to be combined in such a way that the deviation of the mean ray is zero. The refractive index of flint and crown glasses for the mean ray are 1620 and 1.518 respectively. If the refracting angle of the flint prism is `6.0^@`, what would be the refracting angle of the crown prism ?

Answer

B

Explanation

Given that
Refractive index of flint glass `=mu_f=1.620`
Refractive index of crown glass `=m_e=1.518`
Refractive angle of flint proms =`A_f=6^@`
for zero net deviation of mean by
`(mu_1-1)A_f=(mu_e-1)A_c`
`rarr A_c=(mu_f-1)/(mu_c-1)`
`A_f=(1.620-1)/(1.518-1)(6.0)^@=7.2^0`