Question

Critical angle of glass is ${\theta }_1$ and that of water is ${\theta }_2$. The critical angle for water and glass surface would be:
$({\mu }_g=\frac{3}{2},{\mu }_w=\frac{4}{3})$

• A. Less than ${\theta }_2$
  
• B. Between ${\theta }_{1}and{\theta }_2$
  
• C. Greater than ${\theta }_2$
  
• D. Less than ${\theta }_1$

Answer 1

The correct option is C Greater than ${\theta }_2$


$sin{\theta }_1=\frac{1}{{\mu }_g}$ and $sin{\theta }_2=\frac{1}{{\mu }_w}$
Since, ${\mu }_g>{\mu }_w,{\theta }_1<{\theta }_2$
Critical angle $\theta$ between glass and water will be given by
$Sin\theta =\frac{{\mu }_w}{{\mu }_g}$ or $\theta >{\theta }_2$