A polarizer-analyzer set is adjusted such that the intensity of light coming out of the analyzer is just 10 % of the original intensity. Assuming that the polarizer-analyzer set does not absorb any light, the angle by which the analyser need to be rotated further to reduce the output intensity to be zero is

Concept: 

To solve this problem, we can use Malus's Law, which states that the intensity of light passing through a polarizer-analyzer set is given by:

\(I = I_0Cos^2φ\)

Calculation:

So, 0.1Io = Iocos2φ

⇒ cosφ = √0.1

⇒ cosφ = 0.316

Since, cos φ < cos 45o therefore, φ > 45° If the light is passing at 90° from the plane of polaroid, than its intensity will be zero.

Then, θ = 90° − φ therefore, θ will be less than 45°. So, the only option matching is option d which is 18.4°

∴ The Correct answer is Option (4): 18.4°