Two beams of red and violet colours are made to pass separately through a prism (angle of the prism is…
Two beams of red and violet colours are made to pass separately through a prism (angle of the prism is $60^{\circ}$ ). In the position of minimum deviation, the angle of refraction will be
$30^{\circ}$ for both the colours
greater for the violet colour
greater for the red colour
equal but not $30^{\circ}$ for both the colours
Solution
At minimum deviation $\left(\delta=\delta_m\right)$ :
$
r_1=r_2=\frac{A}{2}=\frac{60^{\circ}}{2}=30^{\circ}
$
(For both colours)
$\therefore$ correct answer is (a)