Question

An unpolarized light beam is incident on the polarizer of a polarization experiment and the intensity of the light beam emerging from the analyzer is measured as $100Lumens$. Now, if the analyzer is rotated around the horizontal axis (direction of light) by $30°$ in clockwise direction, the intensity of emerging light will be________ Lumens.

Answer 1

Step 1: Given data:

The intensity of incident light, $I_0=100lumens$

The angle of incidence on the polarizer, $\theta =30°$

Step 2: Finding out the intensity of emerging light:

Using,

$\begin{array}{rcl}{I}_{net}& =& I_0{\cos }^2\theta \\ & =& 100\times {(\sqrt{3}/2)}^2\\ & =& 100\times 3/4\\ & =& 75lumens\end{array}$

Hence, the intensity of emerging light will be $\mathbf{75}\mathbf{}\mathit{L}\mathit{u}\mathit{m}\mathit{e}\mathit{n}\mathit{s}$.