Question

A crown glass prism of refracting angle $6^{\circ }$ is to be used for deviation without dispersion with a flint glass of angle of prism a.Given: for crown glass ${\mu }_r=1.513$ and ${\mu }_v=1.523$, for flint glass ${\mu }_r=1.645$ and ${\mu }_v=1.665$. Find a.

• A. $3^{\circ }$
• B. $4^{\circ }$
• C. ${4.5}^{\circ }$
• D. $5^{\circ }$

Answer 1

The correct option is A $3^{\circ }$

$({\mu }_{v_1}-{\mu }_{r_1})a_1=({\mu }_{v_2}-{\mu }_{r_2})a_2$
$or{a}_2=\frac{(1.523-1.513)}{(1.665-1.645)}{6}^{\circ }=3^{\circ }$