Question

Find the dispersive power of flint glass. The refractive indices of flint glass for red, yellow and violet lights are $1.613,1.620$ and $1.632$ respectively.

• A. $0.0612$
• B. $0.310$
• C. $0.0306$
• D. $0.001$

Answer 1

The correct option is C $0.0306$

Given, ${\mu }_r=1.613;{\mu }_y=1.620;{\mu }_v=1.632$

The dispersive power is given by,

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

$\omega =\frac{1.632-1.613}{1.620-1}=\frac{0.019}{0.620}=0.0306$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(C\right)$ is the correct answer.

Why this question ? To test the basic understanding of the dispersive power.