Unpolarised light is passed through a polaroid `P_(1)`. When this poalrised beam passes through another polaroid `P_(2)`, and if the pass axis of `P_(2)` makes an angle `theta` with pass axis of `P_(1)`, then write the expression for the polarised beam passing through `P_(2)`. Draw a plot showing the variation of intensity when `theta` varies from 0 to 2 `pi`.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Understand the Situation
We have unpolarized light passing through a polaroid \( P_1 \), which polarizes the light. The intensity of the unpolarized light before passing through \( P_1 \) is \( I_0 \).

### Step 2: Determine the Intensity After \( P_1 \)
When unpolarized light passes through the first polaroid \( P_1 \), the intensity of the polarized light that emerges from \( P_1 \) is given by:
\[
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