Easy INTEGER +4 / -1 PYQ · JEE Mains 2021

A parallel plate capacitor of capacitance 200 $\mu$F is connected to a battery of 200 V. A dielectric slab of dielectric constant 2 is now inserted into the space between plates of capacitor while the battery remain connected. The change in the electrostatic energy in the capacitor will be ____________J.

Answer (integer) 4

Solution

$\Delta U = {1 \over 2}(\Delta C){V^2}$<br><br>$\Delta U = {1 \over 2}(KC - C){V^2}$<br><br>$\Delta U = {1 \over 2}(2 - 1)C{V^2}$<br><br>$\Delta U = {1 \over 2} \times 200 \times {10^{ - 6}} \times 200 \times 200$<br><br>$\Delta U = 4$ J

About this question

Subject: Physics · Chapter: Electrostatics · Topic: Dielectrics

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