Assertion: In an $AC$, only capacitor circuit instantaneous power at any instant of time is zero.

Reason: Phase difference between current function and voltage function is $90°$.

Assertion: When a ferromagnetic rod is inserted inside an inductor, then current in $L-C-R$, alternating circuit will decrease.

Reason: By inserting the ferromagnetic rod inside the inductor, the coefficient of self-induction and hence the net impedance will increase.

Assertion: A capacitor is not connected in a $DC$ circuit.

Reason: In $DC$ circuit current through capacitor circuit becomes zero in steady-state.

Assertion: Average value of current in half cycle of an $AC$ Circuit cannot be zero.

Reason: For positive half-cycle average value of current is $\frac{2}{\pi }{i}_0$ 

Assertion: An $AC$ can be transmitted over long distances without much power loss.

Reason: An $AC$ can be stepped up or down with the help of a transformer.

Assertion: In $L-C-R$ series $AC$ circuit  $X_{\mathrm{L}}=X_{\mathrm{C}}=R$ at a given frequency. When this frequency is doubled, the impedance of the circuit is $\frac{\sqrt{13}}{2}R$.

Reason: The given frequency is resonance frequency.

Assertion: At resonance power factor of series $L-C-R$ circuit is zero.

Reason: At resonance current function and voltage functions are in the same phase.