A 900 pF capacitor is charged by 100V battery.
(a) How much electrostatic energy is strored by the capacitor ? The capacitor is disconnected from the battery and connected to another 900 pF capacitor. How much is the electrostatic energy stored in the system ?

Explanation

To solve the problem step by step, we will first calculate the electrostatic energy stored in the first capacitor when charged by the battery, and then determine the energy stored in the system after connecting the second capacitor.

### Step 1: Calculate the Electrostatic Energy Stored in the First Capacitor

The formula for the electrostatic energy (U) stored in a capacitor is given by:

\[ U = \frac{1}{2} C V^2 \]

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