Question

Prism angle of a glass prism is ${10}^o$. It's refractive index of red and violet color is $1.51$ and $1.52$ respectively. Then its dispersive power will be

• A. $0.015$
• B. $0.020$
• C. $0.011$
• D. $0.019$

Answer 1

The correct option is B $0.020$

Angular dispersion $=({\mu }_y-{\mu }_r)\times A^o$

${\mu }_y=1.52$

${\mu }_R=1.51$

$\omega =\frac{{\mu }_v-{\mu }_r}{{\mu }_y-1}$

${\mu }_y=\frac{{\mu }_v+{\mu }_r}{2};=1.515$

$\omega =\frac{0.52-1.51}{0.51-1}=0.020$