Master Electrical Circuits: A Comprehensive Guide for Engineering Students

Question 1

Ohm's Law is expressed mathematically as:

Accepted Answer

V = IR

Answer

I = VR

Answer

R = IV

Answer

V = I

Question 2

In a series circuit, the current through each component is:

Accepted Answer

Equal

Answer

Proportional to the resistance

Answer

Zero

Answer

Dependent on the voltage

Question 3

Kirchhoff's Current Law states that the total current entering a junction must be:

Accepted Answer

Equal to the total current leaving the junction

Answer

Less than the total current leaving the junction

Answer

Greater than the total current leaving the junction

Answer

Independent of the total current leaving the junction

Question 4

The unit of electrical resistance is the:

Accepted Answer

Ohm

Answer

Ampere

Answer

Volt

Answer

Farad

Question 5

A capacitor stores electrical energy primarily in its:

Accepted Answer

Electric field

Answer

Magnetic field

Answer

Gravitational field

Answer

Electromagnetic field

Question 6

A three-phase system typically has three conductors with:

Accepted Answer

Equal voltages and phase differences of 120 degrees

Answer

Equal voltages and phase differences of 90 degrees

Answer

Different voltages and phase angles

Answer

Equal currents and phase differences of 180 degrees

Question 7

The power factor of a circuit is defined as the ratio of:

Accepted Answer

True power to apparent power

Answer

Real power to complex power

Answer

Apparent power to reactive power

Answer

Reactive power to active power

Question 8

How do you calculate the resistance of a circuit component using Ohm's law?

Accepted Answer

Divide the voltage across the component by the current flowing through it

Answer

Multiply the voltage across the component by the current flowing through it

Answer

Subtract the voltage across the component from the current flowing through it

Answer

Add the voltage across the component to the current flowing through it

Question 9

In AC circuits, capacitors and inductors have different functions. What is the key difference in their behaviors?

Accepted Answer

Inductors store energy in a magnetic field, while capacitors store it in an electric field.

Answer

Capacitors hinder AC current flow, while inductors enhance it.

Answer

Capacitors and inductors have minimal impact on AC circuits.

Answer

Capacitors and inductors operate identically in AC circuits.

Question 10

Which of the following is NOT a fundamental electrical circuit law?

Accepted Answer

Ampere's law

Answer

Ohm's law

Answer

Kirchhoff's voltage law

Answer

Kirchhoff's current law

Question 11

In a series circuit, the total resistance is:

Accepted Answer

Equal to the sum of the individual resistances

Answer

Less than the sum of the individual resistances

Answer

Greater than the sum of the individual resistances

Answer

Independent of the individual resistances

Question 12

Which of the following is a characteristic of AC circuits?

Accepted Answer

Current and voltage change direction periodically

Answer

Current and voltage are constant

Answer

Resistance is the only factor affecting current flow

Answer

Capacitance and inductance have no effect on the circuit

Question 13

The phase difference between voltage and current in an inductive circuit is:

Accepted Answer

90 degrees

Answer

0 degrees

Answer

180 degrees

Answer

270 degrees

Question 14

In a parallel circuit, the total current is:

Accepted Answer

Equal to the sum of the individual currents

Answer

Equal to the product of the voltage and resistance

Answer

Less than the sum of the individual currents

Answer

Greater than the sum of the individual currents

Question 15

Capacitance in an AC circuit has the effect of:

Accepted Answer

Shifting the phase of the current

Answer

Increasing the current flow

Answer

Decreasing the current flow

Answer

Increasing the resistance of the circuit

Question 16

The impedance of an AC circuit is a measure of:

Accepted Answer

The opposition to current flow

Answer

The total resistance of the circuit

Answer

The phase difference between voltage and current

Answer

The power factor of the circuit

Question 17

In a parallel circuit, the total current is:

Accepted Answer

Equal to the sum of the individual branch currents

Answer

Equal to the largest individual branch current

Answer

Equal to the smallest individual branch current

Answer

Zero

Question 18

In a series circuit, the voltage drop across each component is:

Accepted Answer

Proportional to its resistance

Answer

Equal to the voltage drop across the entire circuit

Answer

Inversely proportional to its resistance

Answer

Independent of its resistance

Question 19

Which type of circuit provides a continuous path for current flow?

Accepted Answer

Closed circuit

Answer

Open circuit

Answer

Short circuit

Answer

Ground circuit

Question 20

The frequency of an alternating current (AC) circuit is measured in:

Accepted Answer

Hertz

Answer

Volts

Answer

Amps

Answer

Ohms

Question 21

Which of the following is a key difference between AC and DC circuits?

Accepted Answer

AC circuits have a varying current, while DC circuits have a constant current

Answer

AC circuits have a constant current, while DC circuits have a varying current

Answer

AC circuits use higher voltages than DC circuits

Answer

AC circuits are more efficient than DC circuits

Question 22

In a capacitor, the amount of energy stored is proportional to:

Accepted Answer

Capacitance and voltage

Answer

Capacitance and current

Answer

Inductance and voltage

Answer

Inductance and current

Question 23

In a transformer, the ratio of the primary winding turns to the secondary winding turns determines the:

Accepted Answer

Voltage ratio

Answer

Current ratio

Answer

Power ratio

Answer

Frequency ratio

Question 24

Which of these laws is NOT a fundamental electrical circuit law?

Accepted Answer

Faraday's Law

Answer

Ohm's Law

Answer

Kirchhoff's Voltage Law

Question 25

Identify the main hazards associated with electricity and outline the essential precautions to minimize the likelihood of injury.

Accepted Answer

Electrical shock, burns, fires, and explosions; utilize insulated tools, protective gear, and adhere to proper grounding and bonding procedures.

Answer

Cuts, bruises, and sprains; employ sharp tools, wear gloves, and maintain awareness of surroundings.

Answer

Poisoning, asphyxiation, and heatstroke; ensure proper ventilation, avoid confined spaces, and stay hydrated.

Answer

Slips, trips, and falls; maintain clean and organized workspaces, wear appropriate footwear, and be aware of surroundings.

Question 26

In AC circuits, impedance (Z) is calculated as the sum of resistance (R) and reactance (X). How are resistance and reactance related to impedance?

Accepted Answer

Resistance and reactance add together to give impedance.

Answer

Resistance and reactance are multiplied together to give impedance.

Answer

Resistance is subtracted from reactance to give impedance.

Question 27

In a series circuit, the resistors are connected in such a way that:

Accepted Answer

The overall resistance is the sum of the individual resistances

Answer

The total voltage is the sum of the individual voltages

Answer

The total current is the sum of the individual currents

Question 28

In a parallel circuit, the voltage across each branch is:

Accepted Answer

Equal to the total voltage applied to the circuit

Answer

Greater than the total voltage

Answer

Less than the total voltage

Answer

Dependent on the branch resistance

Question 29

The SI unit of electrical resistance is:

Accepted Answer

Ohm

Answer

Volt

Answer

Farad

Answer

Ampere

Question 30

Kirchhoff's current law (KCL) states that the algebraic sum of the currents entering a junction is:

Accepted Answer

Equal to the algebraic sum of the currents leaving the junction

Answer

Dependent on the junction's resistance

Answer

Greater than the total current leaving the junction

Answer

Less than the total current leaving the junction

Question 31

A transformer is primarily used to:

Accepted Answer

Change the voltage level of an AC signal

Answer

Amplify a signal

Answer

Convert AC to DC

Answer

Change the frequency of an AC signal

Question 32

The insulation resistance of a circuit is typically measured using a:

Accepted Answer

Megger

Answer

Multimeter

Answer

Ammeter

Answer

Voltmeter

Question 33

In an electrical circuit, what factor opposes the flow of current?

Accepted Answer

Resistance

Answer

Voltage

Answer

Capacitance

Answer

Inductance

Question 34

Which type of circuit permits current to travel only in a single direction?

Accepted Answer

DC circuit

Answer

AC circuit

Answer

Parallel circuit

Answer

Series circuit

Question 35

When two resistors are connected in series, how is the total resistance calculated?

Accepted Answer

As the sum of their individual resistances

Answer

As the difference between their individual resistances

Answer

As the average of their individual resistances

Answer

As the value of the smallest resistance

Question 36

According to Kirchhoff's Current Law, what occurs at a junction in a circuit?

Accepted Answer

Total current entering equals total current leaving

Answer

Power equals voltage multiplied by amperage

Answer

Voltage across equals sum of voltage drops

Answer

Resistance equals sum of individual resistances

Question 37

What unit of measurement is used to express electrical power?

Accepted Answer

Watt

Answer

Ohm

Answer

Volt

Answer

Ampere

Question 38

Which electrical device transforms alternating current (AC) into direct current (DC)?

Accepted Answer

Rectifier

Answer

Capacitor

Answer

Transistor

Answer

Transformer

Question 39

What unit is used to measure the frequency of AC circuits?

Accepted Answer

Hertz

Answer

Volts

Answer

Ohms

Question 40

A resistor in a circuit has a resistance of 10 ohms and a current of 2 amps flowing through it. What is the voltage across the resistor?

Accepted Answer

20 volts

Answer

40 volts

Answer

5 volts

Answer

10 volts

Question 41

According to Kirchhoff's Current Law, what is the relationship between the currents entering and leaving a junction in a circuit?

Accepted Answer

The sum of currents entering a junction equals the sum of currents leaving the junction.

Answer

The sum of currents entering a junction is independent of the sum of currents leaving the junction.

Answer

The sum of currents entering a junction is always less than the sum of currents leaving the junction.

Answer

The sum of currents entering a junction is always greater than the sum of currents leaving the junction.

Question 42

Two resistors, each with a resistance of 5 ohms, are connected in series. What is the total resistance of this circuit?

Accepted Answer

10 ohms

Answer

5 ohms

Answer

2.5 ohms

Answer

25 ohms

Question 43

Two resistors, each with a resistance of 5 ohms, are connected in parallel. What is the total resistance of this circuit?

Accepted Answer

2.5 ohms

Answer

10 ohms

Answer

5 ohms

Answer

25 ohms

Question 44

What is the standard unit of measurement for electrical power?

Accepted Answer

Watts (W)

Answer

Ohms (Ω)

Answer

Volts (V)

Answer

Amps (A)

Question 45

Which type of electrical current flows in only one direction?

Accepted Answer

Direct Current (DC)

Answer

Triangular Current

Answer

Alternating Current (AC)

Answer

Pulse Current

Question 46

A circuit with high resistance will generally have a ______ current flow.

Accepted Answer

Low

Answer

High

Answer

Constant

Answer

Fluctuating

Question 47

Which of the following factors does NOT directly influence the resistance of a conductor?

Accepted Answer

Voltage applied

Answer

Length of the conductor

Answer

Material of the conductor

Answer

Cross-sectional area of the conductor

Question 48

A circuit has a voltage source of 12 volts and a total resistance of 4 ohms. Calculate the current flowing through the circuit.

Accepted Answer

3 amps

Answer

0.33 amps

Answer

16 amps

Answer

48 amps