Determine the angle of flint glass prism, which should be combined with a crown glass prism of `5^@` so as to give dispersion, but no deviation. Given for crown glass, `mu_v = 1.523, mu_r 1.515` For flint glass, `mu_v' = 1.688, mu_r' = 1.650`.

Explanation

For no deviation
`(A')/A=((mu-1)/(mu'-1))`
or, `A'=((mu-1)/(mu'-1))A`
Now, `mu=(mu_(V)+mu_(R))/2`
`=(1.523+1.515)/2`
`=1.519`
`mu'=(mu_(V)+mu_(R))/2=(1.668+1.650)/2=1.659`
`:. A'=((1.519-1)/(1.659-1))5^(@)=3.94^(@)`