question_answer

An LCR circuit is equivalent to a damped pendulum. In an LCR circuit the capacitor is charged to \[{{Q}_{0}}\]and then connected to the L and R as shown below:

If a student plots graphs of the square of maximum charge \[\left( Q_{Max}^{2} \right)\]on the capacitor with time (t) for two different values \[{{L}_{1}}\] and \[{{L}_{2}}\] \[\left( {{L}_{1}}>{{L}_{2}} \right)\]of L then which of the following represents this graph correctly? (plots are schematic and not drawn of scale)                                                       [JEE MAIN 2015]

A)

B)

C)

D)

Correct Answer: C

Solution :

[c] \[-\frac{q}{C}-iR=\frac{Ldi}{dT}=0\]