A ray of light passing from air through an equilateral glass prism undergoes minimum deviation when the angle of incidence is 34th of the angle of prism. Calculate the speed of light in the prism.
Here, Angle of prism, A=60o
Angle of incidence, i=34×60
i+e=A+δ
e is emergence angle
where δ is deviation angle
At minimum deviation δ=δmin
i=e
2i=A+δmin
2×45=60+δmin
δmin=30
By prism law,
μ=sinA+δmin2sinA2
μ=sin60+302sin602=2√2=1.41
Let v be velocity of light in prism
v=cμ=3×1081.41=2×108 m/s