54. ​Light enters at an angle of incidence in a  transparent rod of refractive index n. For what value 
of the refractive index of the material of the rod the  light once entered into it will not leave it through its 
lateral face whatsoever be the value of angle of  incidence? 

1. n = 1.1


2. n = 1

3. $n > \sqrt{2}$
4. n= 1.3