Define the term 'linearly polarised light'.
When does the intensity of transmitted light become maximum, when a polaroid sheet is rotated between two crossed polaroids ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Linearly Polarized Light:**
- Linearly polarized light is defined as light in which the vibrations of the electromagnetic waves are restricted to a single plane. This means that all the electric field vectors of the light waves oscillate in the same direction.

2. **Understanding Polarization:**
- When unpolarized light (which has vibrations in multiple planes) passes through a polarizing filter (or polaroid), only the component of light that is aligned with the axis of the filter can pass through. This results in light that vibrates in a single plane, thus becoming linearly polarized.

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