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`.

Answer

`- 3.88^(@)`

Explanation

`A = 5^(@), A' = gt, mu_(v) = 1.523, mu_( r) = 1.515`
`mu'_(v) = 1.688, mu_(r ) = 1.650`
`mu = (mu_(v) + mu_(r ))/(2) = (1.523 + 1.515)/(2) = 1.519`
`mu' = (mu_(v)' + mu_(r )')/(2) = (1.688 + 1.650)/(2) = 1.669`
For no deviation, `delta + delta' = 0`
`(mu - 1)A + (mu' - 1)A' = 0`
`A' = (-(mu - 1)A)/((mu' - 1)) = (-(1.519 - 1)5)/((1.669 - 1)) = (-0.519 xx 5)/(0.669)`
`= -3.88^(@)`