[amp_mcq option1=”parallel RL circuit” option2=”parallel RC circuit” option3=”parallel RLC circuit operated above its resonant frequency” option4=”purely resistive circuit E. None of the above” correct=”option4″]
The correct answer is: D. purely resistive circuit
When operating above its resonant frequency, a parallel RLC circuit has the characteristics of a purely resistive circuit. This is because the inductive and capacitive reactances cancel each other out, leaving only the resistance in the circuit.
A parallel RLC circuit is a circuit that contains a resistor, an inductor, and a capacitor connected in parallel. The resonant frequency of a parallel RLC circuit is the frequency at which the inductive and capacitive reactances are equal in magnitude but opposite in sign. At the resonant frequency, the impedance of the circuit is minimum and is equal to the resistance of the circuit.
When the parallel RLC circuit is operated above its resonant frequency, the inductive reactance is negative and the capacitive reactance is positive. The net reactance of the circuit is therefore positive, which means that the circuit behaves like a resistor. The current through the circuit is in phase with the voltage across the circuit, and the power dissipated by the circuit is maximum.
The other options are incorrect because they do not describe the characteristics of a parallel RLC circuit operated above its resonant frequency.
- Option A is incorrect because a parallel RL circuit has a capacitive reactance, which is not present in a parallel RLC circuit operated above its resonant frequency.
- Option B is incorrect because a parallel RC circuit has an inductive reactance, which is not present in a parallel RLC circuit operated above its resonant frequency.
- Option C is incorrect because a parallel RLC circuit operated above its resonant frequency is not a parallel RLC circuit.
- Option E is incorrect because the characteristics of a parallel RLC circuit operated above its resonant frequency are described in the answer.