The critical angle $$\theta c$$ in an optical fiber is given by .............. Where $$n_1$$, is refractive index of medium 1 and $$n_2$$ is the refractive index of medium 2.

A

$$\sin^{-1}(\frac{n_{2}}{n_{1}})$$

B

$$\sin^{-1}(\frac{n_{1}}{n_{2}})$$

C

$$\sin^{-1}({n_{2}} * {n_{1}})$$

D

$$\sin^{-1} n_{2}$$