Question

A straight rod partially immersed in water appears to be inclined at ${45}^{\circ }$ with the surface when viewed vertically through air. What is the actual inclination of the rod? value of n=4/3

• A. ${30}^{\circ }$
• B. ${45}^{\circ }$
• C. ${58}^{\circ }$
• D. ${60}^{\circ }$

Answer 1

The correct option is C ${58}^{\circ }$

The refractive angle is given as,

$\frac{\sin i}{\sin r}=n$

$\frac{\sin {45}^{\circ }}{\sin r}=\frac{4}{3}$

$r={32.11}^{\circ }$

The actual inclination is given as,

$\theta =90-r$

$\theta =90-32.11$

$\theta ={57.89}^{\circ }$