Thank you for reporting, we will resolve it shortly
Q.
An unpolarised beam of intensity $I_0$ is incident on a pair of nicols making an angle of $60^{\circ}$ with each other. The intensity of light emerging from the pair is
After passing from first nicol the intensity will be reduce by $50 \%$
$I'=\frac{ I _{0}}{2}$
Then it will pass from second nicol
According to Malus' law
$I = I _{0} \cos ^{2} \theta= I _{0}\left(\cos ^{2} 60^{\circ}\right)$
$I '\times\left(\frac{1}{2}\right)^{2}=\frac{ I '}{4}=\frac{ I _{0}}{8}$