Fundamentals of Electric Circuits MCQs (Part-3)

What is the unit of electric current?

A Volt
B Ampere
C Ohm
D Watt

What is the basic unit of voltage?

A Ohm
B Ampere
C Volt
D Joule

Which of the following describes the behavior of a purely resistive circuit in AC?

A The voltage and current are out of phase by 90 degrees.
B The voltage and current are in phase.
C The current lags the voltage by 90 degrees.
D The voltage and current are unrelated.

What does the term “transient analysis” in electrical circuits refer to?

A The study of a circuit’s behavior in steady-state conditions.
B The study of a circuit’s behavior when a sudden change in conditions occurs.
C The study of the voltage drop across resistors.
D The calculation of power in AC circuits.

What does the term “steady-state analysis” refer to in electrical circuits?

A The study of short circuits.
B The study of long-term behavior of a circuit.
C The study of behavior during sudden changes.
D The analysis of digital circuits.

What is a phasor in an AC circuit?

A A time-domain representation of current.
B A vector that represents a sinusoidal function in the frequency domain.
C A representation of voltage as a sinusoidal waveform.
D A capacitor in an AC circuit.

What is the resonance condition in an RLC circuit?

A The inductive reactance equals the capacitive reactance.
B The total resistance equals zero.
C The current is minimized.
D The capacitor is fully discharged.

Which of the following is true for a series circuit?

A The total current is divided among the components.
B The total resistance is the sum of individual resistances.
C The total voltage is the same across each component.
D The total resistance is always constant.

What is the total resistance of two resistors, 3 ohms and 6 ohms, connected in parallel?

A 9 ohms
B 2 ohms
C 1.5 ohms
D 4.5 ohms

What happens to the total impedance in a series RLC circuit at resonance?

A The impedance is minimized.
B The impedance is maximized.
C The current is minimized.
D The impedance is constant.

What does the power factor in an AC circuit measure?

A The ratio of voltage to current.
B The total power used by the circuit.
C The ratio of real power to apparent power.
D The voltage drop across the resistor.

What is the primary purpose of an electrical filter in a circuit?

A To amplify signals.
B To remove unwanted frequencies.
C To increase the voltage.
D To store energy.

What is the main role of a transformer in an electrical circuit?

A To convert AC to DC.
B To change the voltage level.
C To regulate the current.
D To store energy.

What is the unit of inductance?

A Farad
B Ohm
C Henry
D Volt

In a DC circuit, what happens if the power factor is 1?

A The circuit is inefficient.
B The circuit uses all the power effectively.
C The circuit has no power loss.
D The current is zero.

What is the purpose of a feedback loop in an amplifier circuit?

A To regulate the voltage.
B To stabilize the output.
C To increase the frequency of operation.
D To store energy.

What is the main function of a diode in a circuit?

A To amplify the signal.
B To allow current to flow in only one direction.
C To store electrical energy.
D To resist the flow of current.

What happens in a parallel circuit when more resistors are added?

A The total current decreases.
B The total resistance decreases.
C The total resistance increases.
D The total voltage increases.

What is the primary purpose of an energy storage component like a capacitor?

A To increase the current.
B To store electrical energy for later use.
C To resist voltage spikes.
D To convert AC to DC.

What is an equivalent circuit used for?

A To simplify the analysis of a complex circuit.
B To add more power to a circuit.
C To increase the current in a circuit.
D To filter out unwanted frequencies.