Electrostatics Question 100
Question: A variable condenser is permanently connected to a 100 $ V $ battery. If the capacity is changed from $ 2\mu F $ to $ 10\mu F $ , then change in energy is equal to [BHU 2000]
Options:
A) $ 2\times {{10}^{-2}}J $
B) $ 2.5\times {{10}^{-2}}J $
C) $ 3.5\times {{10}^{-2}}J $
D) $ 4\times {{10}^{-2}}J $
Show Answer
Answer:
Correct Answer: D
Solution:
$ \Delta U=U _{2}-U _{1}=\frac{V^{2}}{2}(C _{2}-C _{1}) $
$ =\frac{{{(100)}^{2}}}{2}(10-2)\times {{10}^{-6}}=4\times {{10}^{-2}}J $
