Van de Graaff generator is based on …………… discharge.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Van de Graaff Generator**: The Van de Graaff generator is an electrostatic machine that generates high voltages. It operates by accumulating electric charge on a metal dome.

2. **Mechanism of Charge Generation**: The generator uses a moving belt to transport charge to the dome. As the belt moves, it picks up charge from a lower electrode and carries it to the upper electrode (the dome).

3. **Role of Corona Discharge**: The Van de Graaff generator relies on a phenomenon known as corona discharge. This occurs when the electric field around the charged dome becomes strong enough to ionize the surrounding air, allowing the generator to maintain and increase the charge on the dome.

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