RLC Circuits Questions and Answers for Viva

Answer-1: An LRC circuit is a type of electrical circuit that consists of an inductor (L), a resistor (R), and a capacitor (C) connected in series or parallel.

Answer-2: In a series LRC circuit, the components are connected sequentially, while in a parallel LRC circuit, the components are connected across the same voltage source.

Answer-3: At resonance, the capacitive reactance and the inductive reactance cancel each other out, resulting in maximum current flow and minimum impedance.

Answer-4: In a series LRC circuit, the current is maximum and the impedance is minimum at resonance, whereas in a parallel LRC circuit, the voltage across the circuit is maximum at resonance.

Answer-5: The resonance frequency (f_res) of an LRC circuit is given by the formula: f_res = 1 / (2π√(LC)), where L is the inductance and C is the capacitance.

Answer-6: The quality factor (Q) of an LRC circuit measures the selectivity or sharpness of resonance and is given by the ratio of the reactance to the resistance at resonance.

Answer-7: A higher Q factor results in a narrower bandwidth and a sharper resonance peak, indicating better selectivity.

Answer-8: During transient behavior, the currents and voltages in the circuit change over time in response to sudden changes in input, such as switching on or off.

Answer-9: The time constant (𝜏) of an LRC circuit is given by the formula: 𝜏 = L / R, where L is the inductance and R is the resistance.

Answer-10: At resonance, the energy is primarily stored in the magnetic field of the inductor and the electric field of the capacitor. At other frequencies, energy storage varies between the inductor and capacitor depending on reactance.

Answer-11: Damping determines how quickly the oscillations in the circuit decay over time. Overdamped circuits have slow decay, underdamped circuits have oscillations, and critically damped circuits decay as quickly as possible without oscillation.

Answer-12: At resonance, the phase difference between voltage and current is zero, indicating that they are in phase.

Answer-13: The transfer function of an LRC circuit relates the output voltage to the input voltage and is influenced by the values of resistance, inductance, and capacitance in the circuit.

Answer-14: Damping reduces the amplitude of oscillations and slightly lowers the natural frequency of the circuit.

Answer-15: LRC circuits can be configured as bandpass filters, allowing a specific range of frequencies to pass while attenuating others, or as bandstop filters, blocking a specific range of frequencies while passing others.

Answer-16: Increasing the capacitance decreases the resonance frequency and widens the bandwidth of the circuit.

Answer-17: LRC circuits are used in various applications such as filters, oscillators, resonant circuits in radio frequency (RF) systems, and power supplies.

Answer-18: Increasing the capacitance decreases the resonance frequency and widens the bandwidth of the circuit.