The capacitance of a parallel plate capacitor is 400 picofarad and its plates are separated by 2 mm of air
( i) What will be the energy when it is charged to 1500 volts ?
(ii) What will be the potential difference with the same charge if separation is doubled ?
(iii) How much energy is need to double the distance between its plates ?

Explanation

To solve the given problem step by step, we will break it down into three parts as per the question.

### Given Data:
- Capacitance, \( C = 400 \, \text{pF} = 400 \times 10^{-12} \, \text{F} \)
- Separation between plates, \( d = 2 \, \text{mm} = 2 \times 10^{-3} \, \text{m} \)
- Voltage, \( V = 1500 \, \text{V} \)

### (i) Energy when charged to 1500 volts
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