Question

$\text{Assertion:}$- Average Power loss in series $\text{LC}$ circuit is always zero.
$\text{Reason:}$- Average value of voltage and current in A.C. is zero.

• A. Both $\text{Assertion}$ & $\text{Reason}$ are true & the $\text{Reason}$ is a correct explanation of the $\text{Assertion}$.
• B. Both $\text{Assertion}$ & $\text{Reason}$ are true, but $\text{Reason}$ is a correct explanation of the $\text{Assertion}$.
• C. $\text{Assertion}$ is true, but the $\text{Reason}$ is false.
• D. Both $\text{Assertion}$ & $\text{Reason}$ are false.

Answer 1

The correct option is B Both $\text{Assertion}$ & $\text{Reason}$ are true, but $\text{Reason}$ is a correct explanation of the $\text{Assertion}$.

For ideal inductors and capacitors there will be no dissipation of energy. They first take energies and then release them again for an AC circuit.
So
Average Power loss $=0$

Now
Let's say, $V=V_0\sin \omega t$
& $i=i_0\sin (\omega t+\varphi )$

Since both $V$ and $i$ are oscillating sinusoidally with time.

$\therefore <i>=<V>=0$

But for any circuit element in AC even including resistance, $<i>=<V>=0$, but in that case $P\ne 0$.

So both are correct but Reason isn’t the correct explanation of $\text{Assertion}$.

Hence, option $\left(\text{B}\right)$ is correct.