The minimum deviations suffered by red, yellow and violet beam passing through an equilateral transparent prism are `38.4^(@), 38.7^(@)` and `39.2^(@)` respectively. Calculate the dispersive power of the medium.

Answer

B

Explanation

Given that `delta_1=28.4^&@`
`=delta_(ry)=38.7^@, and delta_y=39.2^@`
Dispersive power
`=(mu_y-mu_r)/(mu_y-1)`
`=((mu_y-1)-(mu_y-1))/((mu_y-1))`
`=((delta/A)(delta/A))/(delta_r/A) `[:. Delta=(mu-1)A]`
`rarr A=delta_y-delta_t)/delta_r=((39.2)-(387.4))/(38.7)`
`=(0.8)/38.7=0.0204`