A thin prism `P_(1)` with angle`6^(@)` and made from glass of refractive index 1.54 is combined with another thin prism `P_(2)` of refractive index 1.72 to produce dispersion without deviation. The angle of prism `P_(2)` will be

Options

A. `5^(@)24'`
B. `4^(@)30'`
C. `6^(@)`
D. `8^(@)`

Explanation

To produce dispersion without deviation,
`(A')/(A)=((mu_(y)-1))/((mu_(y)'-1))implies(A')/(6)=-((1.54-1))/((1.72-1))`
`implies A'=-45^(@)=4^(@)30`'