Question

Flint glass prism is joined by a crown glass prism to produce dispersion without deviation. The refractive indices of these for meam ray are $1.602\text{and}1.500$ respectively. Angle of prism of flint prism is ${10}^{\circ }$, then the angle of prism for crown prism will be

• A. ${1.24}^{\circ }$
• B. ${12}^{\circ }$
• C. ${12}^{\circ }{4}^{\prime }$
• D. ${12}^{\circ }{2.4}^{\prime }$

Answer 1

The correct option is D ${12}^{\circ }{2.4}^{\prime }$

We know that: $\frac{A}{A^{\prime }}=\frac{n_Y^{\prime }-1}{n_Y-1}$

Given:

$n_Y^{\prime }=1.602,n_Y=1.500$

Angle of prism for flint glass $\left(A\right)={10}^{\circ }$

$\frac{A}{A^{\prime }}=\frac{n_Y^{\prime }-1}{n_Y-1}$

$\Rightarrow \frac{A}{10}=\frac{1.602-1}{1.500-1}$ $\Rightarrow A={12}^{\circ }{2.4}^{\prime }$