Chapter 24, Problem 46P

To determine

To identify: Whether a piece of material is diamond or not.

Answer to Problem 46P

The given material is diamond.

Explanation of Solution

Given:

Refractive index of material, ${\text{n}}_2=2.42$

Refractive index of oil, $n_1=1.43$

Formula used:

The angle of incidence at which the reflected light is completely plane polarized is termed as Brewster’s angle or polarizing angle.

It is known that: $\tan {\theta }_p=\frac{n_2}{n_1}$

Where,

  ${\theta }_p$ is polarising angle.

  $n$ is refractive index.

Calculation:

Get the polarising angle for an oil-diamond interface, $\tan {\theta }_p=\frac{n_2}{n_1}$

  $\tan {\theta }_p=\frac{n_2}{n_1}=\frac{2.42}{1.43}$

  $\therefore {\theta }_p=59.4°$

According to Brewster angle, a piece of material is diamond.

Conclusion:

A piece of material is diamond.