When a ray of light is incident at an angle of incidence 60° on one face of an equilateral prism the angle of deviation is found to be minimum. The refractive index of the prism material is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $\sqrt{3}$
Angle of Minimum deviation ($δ_{min}$) through the prism -
$δ_{min}=2i-A$ [i = Angle of incidence, A = Angle of prism]
$=2×60-60$
$=60°$
$μ=\frac{\sin\left(\frac{A+δ_{min}}{2}\right)}{\sin\left(\frac{A}{2}\right)}$
$=\frac{\sin\left(\frac{60+60}{2}\right)}{\sin\left(\frac{60}{2}\right)}=\sqrt{3}$