JEE Main & Advanced
Sample Paper
JEE Main - Mock Test - 33
question_answer
In an ideal parallel LC circuit, the capacitor is charged by connecting it to a dc source which is then disconnected. The current in the circuit
A)Becomes zero instantaneously
B)Grows monotonically
C)Decays monotonically
D)Oscillates instantaneously
Correct Answer:
D
Solution :
[d] \[\frac{q}{c}+L\frac{di}{di}=0\Rightarrow \,\frac{{{d}^{2}}q}{d{{t}^{2}}}+\frac{q}{LC}=0\] which is equation of oscillatory motion \[\Rightarrow \,\,\,\,\,q={{q}_{0}}\sin \omega t\Rightarrow \frac{dq}{dt}=i={{q}_{0}}\omega \cos \omega t\] here \[\omega =\frac{1}{\sqrt{LC}}\Rightarrow \] current starts oscillation.