Electrostatics Question 148
Question: If the potential of a capacitor having capacity of 6 mF is increased from 10 V to 20 V, then increase in its energy will be [Pb. PET 2002]
Options:
A) 12 x10^6 J
B) 9 x10^4 J
C) 4 x10^6 J
D) 4 x10^9 J
Show Answer
Answer:
Correct Answer: B
Solution:
The increase in energy of the capacitor
$ \Delta U=\frac{1}{2}C(V _{2}^{2}-V _{1}^{2})=\frac{1}{2}(6\times {{10}^{-6}})(20^{2}-10^{2}) $
$ =3\times {{10}^{-6}}\times 300=9\times {{10}^{-4}}J $
