Statement
Plotting the graph
Calculating value of $\left(\mathit{\mu }\right)$ refractive index
(i) When the pass axis of a polaroid makes an angle $\mathit{\theta }$ with the plane of polarisation of polarised light of intensity ${\mathit{I}}_0$ incident on it, then the intensity of the transmitted emergent light is given by $\mathit{I}={\mathit{I}}_0$ ${\cos }^2\mathit{\theta }$
Note : If the student writes the formula $\mathit{I}={\mathit{I}}_0{\cos }^2\mathit{\theta }$ and draws the diagram give 1 mark
(ii) (iii) $\mathit{\mu }=\tan {\mathit{i}}_{\mathit{\beta }}$
$=\tan {60}^{\circ }=\sqrt{3}=1.7$