Draw a labelled diagram of AC generator. Derive the expression for the instantaneous value of the emf induced in the coil.

Explanation

### Step-by-Step Solution

**Step 1: Draw the Diagram of an AC Generator**
- An AC generator consists of a rectangular coil (loop) of wire that is placed between the poles of a magnet (one north and one south).
- The coil is mounted on a rotor that can rotate.
- The ends of the coil are connected to slip rings, which are in contact with carbon brushes that allow the current to flow out of the generator.

**Labelled Diagram:**
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