Question

Which expression gives the sine of the critical angle for a denser-to-rarer transition?

Options

• \[\sin i_c=\frac{n_1}{n_2}\]

• \[\sin i_c=n_1-n_2\]

• \[\sin i_c=n_1n_2\]

• \[\sin i_c=\frac{n_2}{n_1}\]

Answer 1

The critical-angle equation is \[n_1\sin i_c=n_2\]. Dividing by \[n_1\] gives \[\sin i_c=\frac{n_2}{n_1}\].