Question

Two prisms A and B are in contact with each other.The dispersive powers of A and B are 0.04 and 0.03 respectively.The angular dispersion produced by A is $8^{\circ }$. The net angular dispersion produced by the combination, if the combination does not produce a net deviation is

• A. ${14}^{\circ }$
• B. $8^{\circ }$
• C. $6^{\circ }$
• D. $2^{\circ }$

Answer 1

The correct option is D $2^{\circ }$

$\begin{array}{cc}\frac{{\theta }_1}{{\omega }_1}=\frac{{\theta }_2}{{\omega }_2}& Netangulardispersive\\ & {\theta }_{net}={\theta }_1-{\theta }_2\\ \frac{8}{0.04}=\frac{{\theta }_2}{0.03}& =8-6\\ & =2^{\circ }\\ 6^{\circ }={\theta }_2& \end{array}$