Electric Circuits: Master the Fundamentals of Electricity

Question 1

What is the SI unit of electric current?

Accepted Answer

Ampere

Answer

Volt

Answer

Ohm

Answer

Farad

Question 2

Which of the following factors does not affect the resistance of a conductor?

Accepted Answer

Speed

Answer

Length

Answer

Cross-sectional area

Answer

Material

Question 3

Which law describes the relationship between current, voltage, and resistance in an electric circuit?

Accepted Answer

Ohm's Law

Answer

Kirchhoff's Law

Answer

Lenz's Law

Answer

Coulomb's Law

Question 4

A circuit has a total resistance of 10 ohms. If a current of 2 amps flows through the circuit, what is the voltage across the circuit?

Accepted Answer

10 volts

Answer

5 volts

Answer

20 volts

Answer

50 volts

Question 5

Which of the following is NOT a type of resistor?

Accepted Answer

Capacitor

Answer

Fixed resistor

Answer

Variable resistor

Answer

Thermistor

Question 6

What is the primary purpose of a capacitor in an electric circuit?

Accepted Answer

To store charge

Answer

To regulate voltage

Answer

To increase current

Answer

To decrease resistance

Question 7

Which of the following devices converts electrical energy into light energy?

Accepted Answer

Light bulb

Answer

Battery

Answer

Resistor

Answer

Transistor

Question 8

In a parallel circuit, the current:

Accepted Answer

Is the same in all branches

Answer

Is different in each branch

Answer

Is zero in all branches

Answer

Depends on the resistance of each branch

Question 9

The power dissipated in a resistor is given by the formula:

Accepted Answer

P = I^2R

Answer

P = VI

Answer

P = V^2/R

Answer

P = VR

Question 10

A fuse is a device that:

Accepted Answer

Breaks the circuit when the current exceeds a certain value

Answer

Provides a low resistance path for current to flow

Answer

Stores electrical energy

Answer

Regulates the voltage in a circuit

Question 11

Which of the following mathematical expressions represents Ohm's Law?

Accepted Answer

V = IR

Answer

I = VR

Answer

R = IV

Answer

V = RI

Question 12

Which type of resistor exhibits a resistance that varies in response to temperature changes?

Accepted Answer

Thermistor

Answer

Fixed resistor

Answer

Variable resistor

Answer

Photoresistor

Question 13

What is the primary function of a fuse in an electric circuit?

Accepted Answer

Protecting the circuit from excessive current

Answer

Regulating the voltage in the circuit

Answer

Storing electrical energy in the circuit

Answer

Allowing current to flow in only one direction

Question 14

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

Accepted Answer

Voltage applied to the conductor

Answer

Length of the conductor

Answer

Cross-sectional area of the conductor

Answer

Material composition of the conductor

Question 15

Which of the following is an example of a series circuit?

Accepted Answer

A circuit where components are connected in a single loop

Answer

A circuit where components are connected in parallel

Answer

A circuit where components are connected in a combination of series and parallel

Answer

A circuit where components are not connected

Question 16

Which of the following is NOT a safety precaution when working with electrical circuits?

Accepted Answer

Touch live wires with bare hands

Answer

Wear appropriate protective gear

Answer

Use insulated tools

Answer

Work in a well-lit area

Question 17

A fuse is primarily used to:

Accepted Answer

Protect against overcurrent

Answer

Regulate voltage in a circuit

Answer

Store electrical energy

Answer

Amplify current

Question 18

A voltmeter is used to measure:

Accepted Answer

Voltage

Answer

Current

Answer

Resistance

Answer

Power

Question 19

The SI unit of current is:

Accepted Answer

Ampere

Answer

Volt

Answer

Ohm

Answer

Joule

Question 20

Ohm's law states that the current through a conductor is proportional to:

Accepted Answer

Voltage

Answer

Resistance

Answer

Power

Answer

Capacitance

Question 21

A 10Ω resistor is connected to a 12V battery. Calculate the current flowing through the resistor:

Accepted Answer

0.83 A

Answer

1.2 A

Answer

12 A

Answer

83 A

Question 22

Which factor does NOT affect the resistance of a conductor?

Accepted Answer

Frequency of the applied voltage

Answer

Length

Answer

Area of cross-section

Answer

Material

Question 23

In a series circuit, the total resistance is:

Accepted Answer

Equal to the sum of the individual resistances

Answer

Greater than the sum of the individual resistances

Answer

Less than the sum of the individual resistances

Answer

Dependent on the voltage of the circuit

Question 24

What is the function of a fuse in an electrical circuit?

Accepted Answer

To prevent excessive current flow

Answer

To increase the voltage of the circuit

Answer

To store electrical energy

Answer

To regulate the frequency of the current

Question 25

Which is an example of a parallel circuit?

Accepted Answer

String of Christmas lights

Answer

Flashlight

Answer

Car battery

Answer

Toaster

Question 26

Which equation represents the relationship between power, current, and voltage?

Accepted Answer

Power = Current x Voltage

Answer

Power = Voltage / Current

Answer

Current = Power / Voltage

Answer

Voltage = Power / Current

Question 27

Which of the following is a renewable source of electrical energy?

Accepted Answer

Hydroelectric

Answer

Coal

Answer

Natural gas

Answer

Nuclear

Question 28

What is the primary purpose of an electrical transformer?

Accepted Answer

To change the voltage of a circuit

Answer

To convert AC to DC

Answer

To control the current in a circuit

Answer

To store electrical energy

Question 29

Which of the following is the standard international (SI) unit of electric current?

Accepted Answer

Ampere (A)

Answer

Volt

Question 30

Ohm's law relates which three electrical quantities?

Accepted Answer

Current (I), Voltage (V), and Resistance (R)

Answer

V = IR

Question 31

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

Accepted Answer

Current

Answer

Cross-sectional area

Question 32

What is the primary function of a fuse in an electrical circuit?

Accepted Answer

Protect the circuit from excessive current flow

Answer

To increase the voltage

Question 33

How do conductors differ from insulators in terms of electric current?

Accepted Answer

Conductors allow current to flow easily, while insulators impede its flow.

Answer

Insulators allow current to flow easily, while conductors do not

Question 34

Which of the following is the SI unit of electric current?

Accepted Answer

Ampere (A)

Answer

Ohm

Answer

Coulomb

Answer

Amp

Question 35

A circuit breaker is a device that:

Accepted Answer

Automatically breaks the circuit when the current exceeds a safe level, preventing damage to the circuit

Answer

Increases the voltage in a circuit

Answer

Measures the resistance of a circuit

Question 36

According to Ohm's law, the current (I) flowing through a conductor is:

Accepted Answer

Directly proportional to the voltage (V) across the conductor

Answer

Proportional to the square of the voltage (V) across the conductor

Answer

Inversely proportional to the voltage (V) across the conductor

Answer

Independent of the voltage (V) across the conductor

Question 37

In a parallel circuit, the total current is:

Accepted Answer

Equal to the sum of the currents flowing through each branch

Answer

Equal to the current flowing through the branch with the highest resistance

Answer

Equal to the current flowing through the branch with the lowest resistance

Question 38

A voltmeter is used to measure:

Accepted Answer

Voltage (V) in a circuit

Answer

Resistance (R)

Answer

Power (P)

Answer

Current (I)

Question 39

A fuse is a safety device:

Accepted Answer

That melts and breaks the circuit if the current exceeds a safe level, protecting the circuit from damage

Answer

Measures the resistance of a circuit

Answer

Increases the voltage in a circuit

Question 40

In a series circuit, the total resistance is:

Accepted Answer

Equal to the sum of the resistances of all components in the circuit

Answer

Equal to the resistance of the component with the highest resistance

Answer

Equal to the resistance of the component with the lowest resistance

Question 41

Which of the following materials is an electrical conductor?

Accepted Answer

Copper

Answer

Rubber

Answer

Plastic

Answer

Wood

Question 42

In the International System of Units (SI), what is the unit used to measure electric current?

Accepted Answer

Ampere (A)

Answer

Ohm (Ω)

Answer

Farad (F)

Answer

Volt (V)

Question 43

Ohm's Law describes the relationship between which three electrical quantities?

Accepted Answer

Voltage, Current, and Resistance

Answer

Inductance, Capacitance, and Resistance

Answer

Voltage, Capacitance, and Inductance

Answer

Current, Resistance, and Power

Question 44

In an electric circuit, what is the arrangement of components known as when they're connected side-by-side along the same path?

Accepted Answer

Parallel

Answer

Combination

Answer

Series

Answer

Closed Loop

Question 45

In a series circuit, how does the total resistance compare to the individual resistances?

Accepted Answer

Equal to the sum of the individual resistances

Answer

Greater than the sum of the individual resistances

Answer

Less than the sum of the individual resistances

Answer

Equal to the smallest individual resistance

Question 46

What is the primary function of a fuse in an electrical circuit?

Accepted Answer

To protect the circuit by breaking the circuit when excessive current flows

Answer

To increase voltage in a circuit

Answer

To store electrical energy

Answer

To reduce resistance in a circuit

Question 47

Which electronic component is used to convert alternating current (AC) to direct current (DC)?

Accepted Answer

Rectifier

Answer

Transistor

Answer

Capacitor

Answer

Resistor

Question 48

In an electric circuit, what is the mathematical relationship between voltage, current, and power?

Accepted Answer

Power = Voltage × Current

Answer

Voltage = Power / Current

Answer

Current = Voltage / Power

Answer

Voltage + Current = Power

Question 49

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

Accepted Answer

To change voltage or current levels

Answer

To store electrical energy

Answer

To regulate current flow

Answer

To protect a circuit from overloads