Q.

A ray of light is incident at the glass-water interface at an angle i. It emerges finally parallel to the surface of water. Then the value of μg would be                   [2003]

1 (43)sini  
2 1sini  
3 43  
4 1  

Ans.

(2)

From Snell's law, μgsini=μairsin90°

∴  μg=1sini