Physics - Wave Optics Question with Solution | TestHub

Let the intensity of unpolarised light be ${\mathrm{I}}_0$, so the intensity of first polaroid is $\frac{{\mathrm{I}}_0}{2}$. On rotating through $60^{\circ }$, the intensity of light from second polaroid $\mathrm{I}=\left(\frac{{\mathrm{I}}_0}{2}\right)(\cos 60{)}^2=\frac{{\mathrm{I}}_0}{2}\frac{1}{4}=\frac{{\mathrm{I}}_0}{8}=0.125{\mathrm{I}}_0$ $\therefore$ percentage of incident light transmitted through the system $=12.5\%$.