question_answer

The critical angle for glass-air interface is \[{{i}_{c}}\]. Will the critical angle for glass-water interface be greater than or less than \[{{i}_{c}}\]?

Answer:

                 For glass-air interface, \[\sin {{i}_{c}}=\frac{1}{^{a}{{\mu }_{g}}}\] The critical angle \[i_{c}^{'}\] for glass-water interface is given by \[\sin i_{c}^{'}=\frac{1}{^{w}{{\mu }_{g}}}\] Now \[^{w}{{\mu }_{g}}{{<}^{a}}{{\mu }_{g}}\] \[\therefore \]  \[\sin i_{c}^{'}>\sin {{i}_{c}}\] or            \[i_{c}^{'}>{{i}_{c}}.\]