Which of the following option shows the Brewster's law in polarisation of light?

$\mu \cot i_B=1$

The correct answer is Option (3) → $\mu \cot i_B=1$

Brewster's law states that the reflected light is completely polarised when the angle of incidence $(i_{B})$ satisfies the relationship-

$\tan i_{B}=μ$

$⇒\frac{μ}{\tan i_{B}}=μ1$

$⇒\mu \cot i_B=1$