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 ot scale) [JEE Main Solved Paper-2015 ]

A)                                                

B)

C)                                                

D) (d)

Correct Answer: C

Solution :

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