Electric Circuits: Master the Fundamentals of Electricity

Question 1

Which type of resistor has a resistance that varies with temperature?

Accepted Answer

Thermistor

Answer

Fixed resistor

Answer

Variable resistor

Answer

Photoresistor

Question 2

Which type of circuit allows current to flow in only one direction?

Accepted Answer

DC circuit

Answer

Series circuit

Answer

Parallel circuit

Answer

AC circuit

Question 3

What is the key distinction between a conductor and an insulator?

Accepted Answer

Conductors allow current to flow easily, while insulators do not

Answer

Insulators allow current to flow easily, while conductors do not

Answer

Conductors have high resistance, while insulators have low resistance

Answer

Insulators have high resistance, while conductors have low resistance

Question 4

Which of these factors does NOT influence the resistance of a wire?

Accepted Answer

Voltage

Answer

Length

Answer

Thickness

Answer

Temperature

Question 5

Which of these is NOT a crucial safety precaution when working with electric circuits?

Accepted Answer

Work on a wet surface

Answer

Avoid touching live wires

Answer

Always wear protective gloves

Answer

Use insulated tools

Question 6

Describe the fundamental difference between a closed circuit and an open circuit.

Accepted Answer

Closed circuit: current flows; Open circuit: no current

Answer

Open circuit: current flows; Closed circuit: no current

Answer

Closed circuit: higher resistance; Open circuit: lower resistance

Answer

Open circuit: higher resistance; Closed circuit: lower resistance

Question 7

In a simple circuit, a 9V battery is connected in series with a 10Ω resistor and a voltmeter. What will the voltmeter display?

Accepted Answer

9V

Answer

10V

Answer

0V

Question 8

Which of the following is NOT a unit of electric current?

Accepted Answer

Volt

Answer

Ampere

Answer

Coulomb per second

Answer

Microampere

Question 9

The equivalent resistance of a series circuit is:

Accepted Answer

Equal to the sum of the resistances of all resistors

Answer

Less than the resistance of any individual resistor

Answer

Greater than the resistance of any individual resistor

Answer

Equal to the smallest resistance in the circuit

Question 10

One advantage of parallel circuits is:

Accepted Answer

Multiple paths for current flow

Answer

Reduced overall resistance

Answer

Dependent control of devices

Answer

Increased voltage drop across each device

Question 11

A circuit that contains only series connections is a:

Accepted Answer

Series circuit

Answer

Parallel circuit

Answer

Mixed circuit

Answer

Open circuit

Question 12

Ohm's law describes the relationship between:

Accepted Answer

Current, voltage, and resistance

Answer

Voltage, resistance, and power

Answer

Current, power, and resistance

Answer

Power, voltage, and current

Question 13

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 14

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

Accepted Answer

Motor

Answer

Battery

Answer

Resistor

Answer

Capacitor

Question 15

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

Accepted Answer

Fossil fuels

Answer

Nuclear power

Answer

Solar power

Answer

Hydroelectric power

Question 16

In a parallel circuit, the total current is what compared to the sum of the individual currents?

Accepted Answer

Equal to

Answer

Less than

Answer

Greater than

Answer

Independent of

Question 17

Which of the following is a characteristic of a superconducting material?

Accepted Answer

Zero resistance

Answer

High resistance

Answer

Low conductivity

Answer

High permeability

Question 18

A fuse is used in a circuit to:

Accepted Answer

Protect the circuit from excessive current

Answer

Increase the current flow in the circuit

Answer

Reduce the voltage in the circuit

Answer

Store energy in the circuit

Question 19

A 10 microfarad capacitor is charged to a potential difference of 10 volts. How much energy is stored in the capacitor?

Accepted Answer

0.5 joules

Answer

0.05 joules

Answer

5 joules

Answer

50 joules

Question 20

A transformer is used to:

Accepted Answer

Change the voltage and current in a circuit

Answer

Store energy in a circuit

Answer

Protect a circuit from overloads

Answer

Filter out unwanted frequencies

Question 21

What is the SI unit of electric current?

Accepted Answer

Ampere (A)

Answer

Ohm (Ω)

Answer

Volt (V)

Answer

Farad (F)

Question 22

In an electric circuit, the current is 5 A and the voltage is 12 V. What is the resistance of the circuit?

Accepted Answer

2.4 Ω

Answer

6 Ω

Answer

12 Ω

Answer

24 Ω

Question 23

Which material is a good conductor of electricity?

Accepted Answer

Copper (Cu)

Answer

Plastic (PE)

Answer

Rubber (C8H13N)

Answer

Wood (cellulose)

Question 24

In a series circuit, the total resistance (R_total) is calculated as:

Accepted Answer

R_total = R1 + R2 + R3

Answer

R_total = (R1 + R2 + R3) / 3

Answer

R_total = R1 × R2 × R3

Answer

R_total = 1 / (1/R1 + 1/R2 + 1/R3)

Question 25

What is the SI unit of electric current?

Accepted Answer

Ampere (A)

Answer

Volt

Question 26

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

Accepted Answer

To prevent damage to the circuit by breaking the circuit when the current exceeds a certain value.

Answer

To increase the voltage in the circuit

Question 27

Which of the following materials is a conductor of electricity?

Accepted Answer

Copper

Answer

Plastic

Question 28

What is the SI unit for measuring electrical resistance?

Accepted Answer

Ohm (Ω)

Answer

Volt

Question 29

In a simple circuit, the voltage (V) across a resistor is directly proportional to the current (I) flowing through the resistor. This relationship is described by which law?

Accepted Answer

Ohm's law

Answer

Gauss's law

Answer

Coulomb's law

Answer

Kirchhoff's voltage law

Question 30

The standard unit of resistance in the SI system is the:

Accepted Answer

ohm

Answer

ampere

Answer

volt

Answer

coulomb

Question 31

In a series circuit, the total resistance is:

Accepted Answer

The sum of the individual resistances

Answer

The average of the individual resistances

Answer

The difference between the individual resistances

Answer

The product of the individual resistances

Question 32

Which of the following materials is a good conductor of electricity? Materials that allow electric current to flow through them easily are classified as good conductors.

Accepted Answer

Copper

Answer

Wood

Answer

Rubber

Answer

Plastic

Question 33

What is the SI unit of electric current?

Accepted Answer

Ampere

Answer

Volt

Answer

Ohm

Answer

Watt

Question 34

Which of the following equations represents Ohm's law?

Accepted Answer

V = IR

Answer

I = VR

Answer

V = I/R

Answer

R = VI

Question 35

In a series circuit, how are the components connected?

Accepted Answer

Components are connected one after the other

Answer

Components are connected in parallel

Answer

Components are connected in a triangle

Question 36

When two resistors are connected in parallel, what happens to their combined resistance compared to their individual resistances?

Accepted Answer

Less than either individual resistance

Answer

Equal to the sum of both resistances

Answer

Equal to the difference of both resistances

Answer

Greater than either individual resistance

Question 37

Which of these devices transforms electrical energy into mechanical energy?

Accepted Answer

Motor

Answer

Capacitor

Answer

Resistor

Answer

Battery

Question 38

What is the main purpose of a fuse in a circuit?

Accepted Answer

To protect the circuit from excessive current

Answer

To generate heat

Answer

To store energy

Answer

To increase the voltage

Question 39

Which equation represents the relationship between voltage (V), current (I), and resistance (R) in a circuit?

Accepted Answer

V = IR

Answer

V = I/R

Answer

I = VR

Answer

R = VI

Question 40

What is the standard unit for measuring electric current?

Accepted Answer

Ampere (A)

Answer

Coulomb (C)

Answer

Ohm (Ω)

Answer

Volt (V)

Question 41

A closed circuit is one where:

Accepted Answer

There's a complete, uninterrupted path for the flow of electric current.

Answer

The switch is open.

Answer

The resistance is low.

Answer

The voltage is high.

Question 42

According to Ohm's Law, how is the current (I) in a conductor related to the voltage (V) across it and its resistance (R)?

Accepted Answer

Current is directly proportional to voltage and inversely proportional to resistance.

Answer

Current is inversely proportional to resistance.

Answer

Current is independent of voltage and resistance.

Answer

Current is directly proportional to voltage.

Question 43

A 10-ohm resistor is connected to a 12-volt battery. What is the current flowing through the resistor?

Accepted Answer

1.2 amps

Answer

12 amps

Answer

0.12 amps

Answer

2.4 amps

Question 44

Which of these materials is a good conductor of electricity?

Accepted Answer

Copper

Answer

Wood

Answer

Plastic

Answer

Rubber

Question 45

What is the primary function of a circuit breaker?

Accepted Answer

To interrupt the flow of current if it exceeds a safe level, preventing overheating and potential fires.

Answer

To convert AC current to DC current.

Answer

To store electrical energy.

Answer

To increase the voltage in a circuit.

Question 46

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

Accepted Answer

To increase or decrease the voltage of an alternating current (AC).

Answer

To store electrical energy.

Answer

To protect a circuit from excessive current.

Answer

To convert AC current to DC current.