A crown glass of refracting angle 8^@ is combined with a flint glass prism to obtain deviation without dispersion. If the refractive indices for red and violet rays for crown glass are 1.514 and 1.524 and for the flint glass are 1.645 and 1.665 respectively, Find the angle of flint glass prism and net deivation.

A crown glass of refracting angle 8^@ is combined with a flint glass p

1.	A crown glass of refracting angle 8^@ is combined with a flint glass prism to obtain deviation without dispersion. If the refractive indices for red and violet rays for crown glass are 1.514 and 1.524 and for the flint glass are 1.645 and 1.665 respectively, Find the angle of flint glass prism and net deivation.
Answer» Solution :The CONDITION for deviation with out DISPERSIONIS `(mu_v-mu_R) A=(mu_v-mu_R)A.` `therefore A.=((1.524 -1.514) times 8^@)/((1.665 -1.645))=0.08^@/0.02=4^@` for crown glass `MU=(1.514+1.524)/2=1.519` for FLINT glass `mu=(1.645+1.665)/2=1.655` `therefore ` The net deviation `(delta-delta.)=(mu-1)A-(mu.-1)A.` `=0.159 times 8^@-0.655 times 4^@=1.53^@`