Electrical Circuits: Master AC and DC Concepts with Interactive Quizzes

Question 1

In a series AC circuit at resonance, what is the relationship between the voltage across the capacitor (VC) and the voltage across the inductor (VL)?

Accepted Answer

VC and VL are equal in magnitude and in phase with each other.

Answer

VC and VL are equal in magnitude but 180 degrees out of phase with each other.

Answer

VC is greater than VL.

Answer

VL is greater than VC.

Question 2

What characteristic is exclusive to DC circuits?

Accepted Answer

Voltage remains constant

Answer

Current reverses direction periodically

Answer

Power factor can be below 1

Question 3

In a DC circuit, the electrical current flows in a:

Accepted Answer

Unidirectional manner

Answer

Alternating manner

Answer

Bidirectional manner

Answer

Random manner

Question 4

The waveform of an AC voltage is predominantly:

Accepted Answer

Sinusoidal

Answer

Triangular

Answer

Square

Answer

Sawtooth

Question 5

In a purely inductive circuit, the phase difference between voltage and current is:

Accepted Answer

90 degrees

Answer

0 degrees

Answer

180 degrees

Answer

45 degrees

Question 6

Resonance occurs in a circuit when:

Accepted Answer

Inductive reactance equals capacitive reactance

Answer

Capacitive reactance is greater than inductive reactance

Answer

Inductive reactance is greater than capacitive reactance

Answer

Resistance is equal to zero

Question 7

The voltage across a capacitor in an AC circuit is:

Accepted Answer

90 degrees out of phase with the current

Answer

45 degrees out of phase with the current

Answer

In phase with the current

Answer

180 degrees out of phase with the current

Question 8

Which component is NOT typically found in an AC circuit?

Accepted Answer

Battery

Answer

Inductor

Answer

Resistor

Answer

Capacitor

Question 9

The unit of electrical resistance is:

Accepted Answer

Ohm

Answer

Ampere

Answer

Volt

Answer

Watt

Question 10

In a series circuit, the equivalent resistance is:

Accepted Answer

The sum of the individual resistances

Answer

The product of the individual resistances

Answer

The average of the individual resistances

Question 11

In AC circuits, power factor is best defined as:

Accepted Answer

The ratio of real power to apparent power

Answer

The ratio of apparent power to real power

Answer

The ratio of reactive power to real power

Question 12

What is the primary distinction between an AC circuit and a DC circuit?

Accepted Answer

AC circuits have alternating current, while DC circuits have direct current.

Answer

DC circuits have constant voltage, while AC circuits have sinusoidal voltage.

Answer

AC circuits always have a power factor of 1, while DC circuits can have a power factor less than 1.

Answer

DC circuits have sinusoidal current, while AC circuits have constant current.

Question 13

In an AC circuit, the difference in the timing of maximum and minimum values of current and voltage is referred to as:

Accepted Answer

Phase difference

Answer

Waveform difference

Answer

Frequency difference

Answer

Amplitude difference

Question 14

The power factor of a circuit indicates the:

Accepted Answer

Ratio of real power to apparent power

Answer

Ratio of capacitance to resistance

Answer

Ratio of resistance to inductance

Answer

Ratio of voltage to current

Question 15

Resonance in an AC circuit occurs when:

Accepted Answer

Inductive and capacitive reactances cancel each other out

Answer

Current is at its minimum value

Answer

Resistance is at its maximum value

Question 16

In a circuit with resistance of 10 ohms and inductive reactance of 8 ohms, the impedance is approximately:

Accepted Answer

12.8 ohms

Answer

18 ohms

Answer

8 ohms

Answer

10 ohms

Question 17

What is the primary function of a transformer in an AC circuit?

Accepted Answer

To change the voltage or current levels

Answer

To filter out noise

Answer

To convert AC to DC

Answer

To store energy

Question 18

Which of the following is a defining attribute of an alternating current (AC) electrical circuit?

Accepted Answer

Voltage and current vary sinusoidally over time

Answer

Voltage and current remain constant

Answer

Current leads voltage by 90 degrees

Answer

Resistance is the only form of impedance

Question 19

In an AC circuit, frequency is measured in what unit?

Accepted Answer

Hertz (Hz)

Answer

Ohms (Ω)

Answer

Watts (W)

Answer

Volts (V)

Question 20

Which component in an AC circuit does not participate in energy storage?

Accepted Answer

Resistor

Answer

Capacitor

Answer

Inductor

Answer

Battery

Question 21

What does the power factor of an AC circuit represent?

Accepted Answer

The ratio of real power to apparent power

Answer

The ratio of voltage to current

Answer

The phase angle between voltage and current

Answer

The amount of energy stored in the circuit

Question 22

Which of the following circuit types is not associated with DC circuits?

Accepted Answer

Capacitive circuit

Answer

Parallel circuit

Answer

Series circuit

Question 23

Which element is exclusive to DC circuits and not found in AC circuits?

Accepted Answer

Battery

Answer

Inductor

Answer

Resistor

Answer

Capacitor

Question 24

In an AC circuit, resonance occurs when:

Accepted Answer

Inductive and capacitive reactance cancel each other out

Answer

Voltage and current are in phase

Answer

Power factor is zero

Question 25

Which of the following characteristics is exclusive to alternating current (AC) and not direct current (DC)?

Accepted Answer

Reversing polarity at regular intervals

Answer

Facilitates power transmission over extensive distances

Answer

Generated by specific devices known as generators

Answer

Compatible with electronic devices

Question 26

Which term describes the measure of resistance to the flow of AC?

Accepted Answer

Impedance

Answer

Resistance

Answer

Inductance

Question 27

In a series AC circuit, the total impedance is calculated as:

Accepted Answer

Vector sum of individual impedances

Answer

Algebraic sum of individual impedances

Answer

Arithmetic mean of individual impedances

Question 28

Which component stores energy in an electric field?

Accepted Answer

Capacitor

Answer

Resistor

Answer

Inductor

Answer

Diode

Question 29

Resonance in a circuit occurs when:

Accepted Answer

Inductive reactance equals capacitive reactance

Answer

Inductive reactance is zero

Answer

Capacitive reactance is zero

Question 30

In a DC circuit, the current exhibits which characteristic?

Accepted Answer

Constant direction and magnitude

Answer

Alternating direction and magnitude

Answer

Intermittent flow

Answer

Zero value

Question 31

In a sinusoidal waveform, what is the term for the maximum value?

Accepted Answer

Peak value

Answer

Period

Answer

Average value

Answer

Frequency

Question 32

In the context of AC circuits, what does the term 'power factor' directly refer to?

Accepted Answer

The ratio of real power to apparent power.

Answer

The ratio of resistance to reactance.

Answer

The ratio of current to voltage.

Answer

The ratio of inductance to capacitance.

Question 33

Which parameter in AC circuits represents the overall opposition to current flow, including resistance, inductance, and capacitance?

Accepted Answer

Impedance

Answer

Inductance

Answer

Capacitance

Answer

Resistance

Question 34

In the context of AC circuits, what phenomenon occurs when the inductive and capacitive reactances cancel each other out?

Accepted Answer

Resonance

Answer

Maximum impedance

Answer

Phase shift

Question 35

What is the fundamental difference between a series circuit and a parallel circuit?

Accepted Answer

In a series circuit, the current is the same throughout, while in a parallel circuit, the voltage is the same throughout.

Answer

In a series circuit, the voltage is the same throughout, while in a parallel circuit, the current is the same throughout.

Question 36

Ohm's law, as applied to DC circuits, is mathematically expressed as:

Accepted Answer

Voltage = Current × Resistance

Answer

Inductance = Resistance × Capacitance

Answer

Power = Voltage × Current

Answer

Impedance = Resistance + Reactance

Question 37

Kirchhoff's current law states that:

Accepted Answer

The total current entering a junction is equal to the total current leaving the junction.

Answer

The total voltage entering a junction is equal to the total voltage leaving the junction.

Answer

The total power entering a junction is equal to the total power leaving the junction.

Question 38

According to Kirchhoff's voltage law:

Accepted Answer

The sum of the voltages around any closed loop in a circuit is equal to zero.

Answer

The sum of the currents around any closed loop in a circuit is equal to zero.

Answer

The sum of the powers around any closed loop in a circuit is equal to zero.

Question 39

Which waveform accurately represents an alternating current (AC) signal?

Accepted Answer

Sinusoidal

Answer

Square

Answer

Sawtooth

Answer

Triangular

Question 40

Which factor does NOT influence impedance in an AC circuit?

Accepted Answer

Temperature

Answer

Resistance

Answer

Capacitance

Answer

Inductance

Question 41

What effect does resonance produce in an AC circuit?

Accepted Answer

Maximum current flow and minimum impedance

Answer

Random fluctuations in current and voltage

Answer

No change in circuit characteristics

Answer

Increased resistance and decreased voltage

Question 42

What type of capacitor is commonly employed in DC circuits?

Accepted Answer

Electrolytic capacitor

Answer

Film capacitor

Answer

Ceramic capacitor

Answer

Tantalum capacitor

Question 43

What is the primary function of a diode in a DC circuit?

Accepted Answer

To permit current flow in only one direction

Answer

To regulate voltage

Answer

To amplify current

Answer

To filter out noise

Question 44

Which characteristic is associated with a short circuit?

Accepted Answer

Negligible resistance

Answer

Significant potential difference

Answer

Intermittent current flow

Answer

High resistance

Question 45

When working with electrical circuits, what is the most important safety measure to observe?

Accepted Answer

Always disconnect the power supply before handling any components

Answer

Wear gloves and eye protection

Answer

Use a circuit tester

Question 46

What is the key difference between AC and DC circuits?

Accepted Answer

AC circuits use current that flows back and forth, while DC circuits use current that flows in one direction.

Answer

AC circuits are used for household appliances, while DC circuits are used for electronic devices.

Answer

AC circuits use higher voltage than DC circuits.

Answer

AC circuits are more efficient than DC circuits.

Question 47

Which term describes the total opposition to current flow in an AC circuit?

Accepted Answer

Impedance

Answer

Resistance

Answer

Reactance

Answer

Conductance

Question 48

In a series RLC circuit, resonance happens when:

Accepted Answer

The inductive reactance and capacitive reactance are equal.

Answer

The resistance is at its maximum value.

Answer

The voltage across the inductor is zero.

Answer

The current flow is at its minimum value.

Question 49

Which of the following is NOT a typical application of AC circuits?

Accepted Answer

Charging a battery.

Answer

Powering household appliances.

Answer

Transmitting power over long distances.

Answer

Running electric motors.