  Question

# A prism ‘X’ and another ‘Y’ are kept in contact with their refracting angles placed opposite to each other as shown in fig. White light is incident on the combination from the left. Column-I described some situation. Match Column-I with the possible out-comes given in Column-II Column IColumn II(P)The prisms are made of same material and their refracting (1)No deviation, No dispersionangles are equal,i.e A=A' The combination will cause(Q)The prisms are made of same material and their refracting (2)No deviation, Dispersion happensangles are not equal,i.eA≠A′.The combination will cause(R)The prisms are made of different material and their (3)No dispersion , deviation happensrefracting angles are equal i.e.A=A'.Also  the quantityμv−μghas different values for the two prisms. Here μv and μgare the refractive indices for violet and redcolours. The combination will cause.(S)The prisms are made of different materials and their(4)Both deviation and dispersion refracting angles are unequal,A≠A′.AlsohappensAA′=−(μ′−1)(μ−1),where μ is the refractive index for the mean wavelength (yellow) for prism X while μ′is thecorresponding value for prism Y. The combination will cause

A

P 2, Q  2, R  3, S  1

B

P 3, Q  3, R  4, S  1

C

P 1, Q  4, R  4, S  2

D

P 4, Q  2, R  3, S  1

Solution

## The correct option is D P → 1, Q → 4, R → 4, S → 2 ω=μV−μRμ−1 and d=(μ−1)A  Suggest corrections   