A ray is incident at an angle of incidence $i$ on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is $\mu$, then the angle of incidence is nearly equal to :
(1) ${A\over2\mu}$
(2) ${2A\over\mu}$
(3) $\mu A$
(4) $\mu A\over2$
(1) ${A\over2\mu}$
(2) ${2A\over\mu}$
(3) $\mu A$
(4) $\mu A\over2$