A ray of light incident on face `AB` of an equilateral glass prism, shows minimum deviation of `306@` .Calculate the speed of light through the prism.

Explanation

Here, `A = 60^@ , delta_m = 30^@, v = ?`
`mu = sin(A + delta)/(sin A//2) = (sin (60^@ + 30^@)//2)/(sin 60^@//2)`
=`(sin 45^@)/(sin 30^@) = (1// sqrt(2))/(1//2) = (2)/(sqrt(2)) = sqrt(2) = 1.414`
From `mu = ( c)/(v)`,
`v = ( c)/(mu) = (3 xx 10^8)/(1.414) m//s = 2.12 xx 10^8 m//s`.