Question

The LC parallel resonant circuit
(A). Has a very high impedance
(B). Has a very high current
(C). Acts as resistance of very low value
(D). Has zero impedance

Answer 1

Hint: It is the property of the capacitor and inductor to store electrical energy. When resonance condition is reached, the reactance of capacitance matches the reactance of the inductor creating the high resistance circuit.

Complete step-by-step answer:
An LC circuit contains a capacitor and an inductor attached to each other. They are either joined parallel to each other or in series and connected to a source of alternating current.
If the capacitor is charged then its discharges to the inductor which in turn charges the capacitor. The circuit performs oscillations in the sense that the electrical energy is exchanged periodically between the capacitor and the inductor. The resonance condition is created when the reactance of the capacitor matches the reactance of the inductor.
${X_L} = {X_C}$
where ${X_L} = \omega L$ is the reactance of the inductor while ${X_C} = \dfrac{1}{{\omega C}}$ denotes the reactance of the capacitor and $\omega = 2\pi v$ with $v$ as the frequency of oscillations.
The frequency of oscillations is given as
$v = \dfrac{1}{{2\pi \sqrt {LC} }}$
In a parallel resonant circuit, we have the inductor and capacitor joined parallel to each other while a source of alternating current is attached to this parallel combination.
In a parallel LC circuit, the impedance is at its maximum value. Hence, option A is correct.

Note: The effect of high impedance in the parallel resonant circuit is that when the frequency of the input alternating current matches the resonant frequency, that frequency is rejected by the circuit. This property can be used to allow and restrict certain frequency current to flow across a circuit, hence, this circuit is used as a rejector circuit.