Question

If $A$ is the angle of prism, $r$ angle of refraction, then the condition for minimum deviation is

• A. $A=r^2$
• B. $A=2r$
• C. $A=\frac{r}{2}$
• D. $A=r$

Answer 1

Answer: (B)

As $r_1+r_2=A$
At minimum deviation, $r_1=r_2=r$
$\therefore 2r=A$