Electrical Systems Overview: Master the Basics for Construction

Question 1

When working on an electrical circuit, which safety measure should be taken first?

Accepted Answer

Turn off the power supply to de-energize the circuit

Answer

Wear insulated gloves for protection against electrical shock

Answer

Use a voltage tester to check if the circuit is live

Answer

Secure the circuit with a lockout/tagout device to prevent re-energization

Question 2

Which of the following is NOT considered one of the basic building blocks or elements of a basic electrical circuit?

Accepted Answer

Battery - source of electrical energy that powers devices

Answer

Conductor - material that allows electrons to flow through it

Answer

Insulator - material that prevents electrons from flowing through it

Answer

Switch - device that controls the flow of current in a circuit

Question 3

A light fixture in a residential building is not working. Outline the logical steps you should take to troubleshoot and fix the issue.

Accepted Answer

Inspect the light bulb for looseness or burnout; replace it if needed.

Accepted Answer

Examine the electrical connections at the light fixture, switch, and junction box; ensure they are secure.

Accepted Answer

Check the circuit breaker panel or fuse box to determine if the circuit supplying the light fixture has tripped or blown.

Answer

Avoid replacing the light switch immediately without checking other components.

Question 4

What is the primary purpose of a grounding system in an electrical installation?

Accepted Answer

To provide a safe path for electrical current to return to its source

Answer

To protect equipment from electrical surges

Answer

To prevent electrical shocks

Answer

To regulate the flow of electricity

Question 5

Which type of electrical circuit provides only one path for current to flow?

Accepted Answer

Series circuit

Answer

Parallel circuit

Answer

Combination circuit

Answer

Open circuit

Question 6

What is the main function of a transformer in an electrical system?

Accepted Answer

To increase or decrease voltage

Answer

To isolate circuits

Answer

To provide grounding

Answer

To store electrical energy

Question 7

Which safety precaution is the most important to take before working on an electrical system?

Accepted Answer

Turn off the main power supply

Answer

Wear appropriate protective gear

Answer

Test all circuits

Answer

Ground the system

Question 8

Which type of wire is commonly used for electrical wiring in residential buildings?

Accepted Answer

Romex

Answer

Twisted pair

Answer

Coaxial

Answer

Fiber optic

Question 9

What is the key difference between a switch and a circuit breaker?

Accepted Answer

A switch manually controls the flow of electricity, while a circuit breaker automatically trips in case of an overload

Answer

A circuit breaker manually controls the flow of electricity, while a switch automatically trips in case of an overload

Answer

Both are used to control the flow of electricity

Answer

There is no difference between a switch and a circuit breaker

Question 10

Which of the following is the unit of measurement for electrical resistance?

Accepted Answer

Ohm

Answer

Ampere

Answer

Volt

Answer

Watt

Question 11

What is the purpose of a conduit in an electrical system?

Accepted Answer

To provide a pathway for wires to run through

Answer

To protect wires from damage

Answer

To ground the system

Answer

To store electrical energy

Question 12

Which of the following is NOT a type of alternating current (AC) electrical signal?

Accepted Answer

Direct current (DC)

Answer

Sine wave

Answer

Square wave

Answer

Triangular wave

Question 13

What is the primary purpose of an electrical insulator?

Accepted Answer

To prevent the flow of electricity

Answer

To allow the flow of electricity

Answer

To store electrical energy

Answer

To generate electrical energy

Question 14

Which type of wire is typically used for grounding electrical systems?

Accepted Answer

Bare copper wire

Answer

Insulated copper wire

Answer

Aluminum wire

Answer

Coaxial cable

Question 15

What is the primary purpose of the National Electrical Code (NEC)?

Accepted Answer

To establish safety regulations for electrical installations

Answer

To provide guidance on electrical wiring methods

Answer

To define a code of ethics for electricians

Answer

To list approved electrical materials

Question 16

Which of the following tools is primarily used to measure electrical current?

Accepted Answer

Ammeter

Answer

Voltmeter

Answer

Ohmmeter

Answer

Multimeter

Question 17

What is the fundamental difference between AC and DC electricity?

Accepted Answer

AC alternates in polarity, while DC flows in one direction

Answer

AC has a higher voltage than DC

Answer

DC is used for lighting, while AC is used for power

Answer

AC is more efficient than DC

Question 18

What is the primary function of a circuit breaker?

Accepted Answer

To protect electrical circuits from overloads

Answer

To control the flow of electricity in a circuit

Answer

To isolate faulty circuits

Answer

To provide electrical power to a circuit

Question 19

Which of the following methods is considered an appropriate way to connect electrical wires?

Accepted Answer

Using wire nuts or crimp connectors

Answer

Twisting the wires together and taping them

Answer

Soldering the wires together

Answer

Using electrical tape only

Question 20

What's the main purpose of a ground fault circuit interrupter (GFCI) in electrical systems?

Accepted Answer

Detect and stop dangerous ground faults

Answer

Reduce power use and save energy

Answer

Protect against electrical overloads and short circuits

Answer

Isolate electrical circuits for repairs

Question 21

The unit of measurement for electrical current is the:

Accepted Answer

Ampere (Amp)

Answer

Volt

Answer

Ohm

Answer

Watt

Question 22

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

Accepted Answer

Direct current (DC) circuit

Answer

Series circuit

Answer

Parallel circuit

Answer

Alternating current (AC) circuit

Question 23

What is the primary purpose of a fuse in an electrical system?

Accepted Answer

To protect the circuit from overloads

Answer

To control the flow of electricity

Answer

To generate electricity

Answer

To store electricity

Question 24

Which of the following materials is a good conductor of electricity?

Accepted Answer

Copper

Answer

Wood

Answer

Plastic

Answer

Rubber

Question 25

Which type of wire insulation is commonly used in residential construction in the United States?

Accepted Answer

NM-B (Romex)

Answer

THHN

Answer

UF-B

Answer

MC (Metal Clad)

Question 26

When troubleshooting an electrical circuit, the recommended approach is to:

Accepted Answer

Start at the source of power and work towards the load

Answer

Start at the load and work towards the source of power

Answer

Use a trial-and-error approach

Answer

Immediately call a licensed electrician

Question 27

Which of the following is not a commonly used type of electrical wiring in residential construction?

Accepted Answer

Coaxial cable

Answer

Romex

Answer

Conduit

Answer

MC cable

Question 28

In an electrical system, which component is designed to safeguard against excessive current flow and short circuits?

Accepted Answer

Circuit breaker

Answer

Conductor

Answer

Insulator

Answer

Resistor

Question 29

What's the main reason we use electrical outlets in electrical systems?

Accepted Answer

To safely and easily connect electrical devices

Answer

To keep the electrical system safe from too much electricity

Answer

To save electricity for later

Question 30

In basic electrical systems commonly found at construction sites, which component is typically NOT included?

Accepted Answer

Transformers

Answer

Conductors

Answer

Insulators

Answer

Switches

Question 31

The SI unit of electrical current is:

Accepted Answer

Ampere

Answer

Watt

Answer

Ohm

Answer

Volt

Question 32

A circuit provides a closed path for the flow of:

Accepted Answer

Electricity

Answer

Heat

Answer

Water

Answer

Light

Question 33

Which of the following is NOT a recommended safety precaution when working with electricity?

Accepted Answer

Working alone

Answer

Inspecting tools and equipment before use

Answer

Wearing insulated gloves

Answer

Using a voltage tester

Question 34

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

Accepted Answer

Protect against overcurrent

Answer

Regulate voltage

Answer

Store electrical energy

Answer

Provide a ground path

Question 35

Which type of wire is primarily used for grounding in electrical systems?

Accepted Answer

Bare copper wire

Answer

Stranded insulated wire

Answer

Flexible conduit

Answer

Solid aluminum wire

Question 36

What is the fundamental difference between AC and DC current?

Accepted Answer

AC current reverses direction while DC current flows in one direction

Answer

AC current has higher voltage than DC current

Answer

DC current is more efficient than AC current

Question 37

Which of the following is a renewable energy source used to generate electricity on a large scale?

Accepted Answer

Solar power

Answer

Nuclear power

Answer

Coal

Answer

Natural gas

Question 38

What is the main purpose of a transformer in an electrical system?

Accepted Answer

Change voltage and current levels

Answer

Store electrical energy

Answer

Provide overcurrent protection

Answer

Control electrical flow

Question 39

What is the primary purpose of an electrical diagram?

Accepted Answer

Provide a graphical representation of an electrical system

Answer

Test electrical components

Answer

Calculate electrical quantities

Question 40

Which of the following is NOT a fundamental component of an electrical circuit?

Accepted Answer

Water pump

Answer

Source

Answer

Switch

Answer

Load

Question 41

The unit of measurement for electrical current is the:

Accepted Answer

Ampere

Answer

Volt

Answer

Watt

Answer

Ohm

Question 42

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

Accepted Answer

To protect against damage from excessive current

Answer

To regulate voltage flow

Answer

To increase circuit resistance

Answer

To store electrical energy

Question 43

In a residential electrical system, which color wire is typically used for the neutral wire?

Accepted Answer

White

Answer

Red

Answer

Black

Question 44

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

Accepted Answer

To modify voltage levels

Answer

To store electrical energy

Answer

To increase current flow

Answer

To reduce circuit resistance

Question 45

What is the intended function of a ground fault circuit interrupter (GFCI) outlet?

Accepted Answer

To prevent electrical shocks

Answer

To regulate voltage flow

Answer

To store electrical energy

Answer

To increase circuit capacity

Question 46

Which type of electrical insulation is suitable for outdoor use and offers resistance to moisture?

Accepted Answer

XLPE (cross-linked polyethylene)

Answer

Rubber

Answer

Cloth

Answer

PVC (polyvinyl chloride)

Question 47

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

Accepted Answer

To protect the circuit from an overload of current

Answer

To regulate the amount of current flowing through the circuit

Answer

To provide a path for the flow of current

Answer

To store electrical energy

Question 48

Which of the following materials is a good conductor of electricity?

Accepted Answer

Copper

Answer

Wood

Answer

Plastic

Question 49

What is the SI unit of electrical resistance?

Accepted Answer

Ohm

Answer

Ampere

Answer

Farad

Answer

Volt

Question 50

Which of the following is NOT a type of electrical power source?

Accepted Answer

Fuse

Answer

Battery

Answer

Solar panel

Answer

Generator

Question 51

What is the primary function of a transformer in an electrical system?

Accepted Answer

To change the voltage level of an alternating current (AC)

Answer

To protect the circuit from overloads

Answer

To store electrical energy

Question 52

Which of the following is an important safety rule when working with electricity?

Accepted Answer

Always turn off the power before working on electrical equipment

Answer

Use bare hands to touch electrical wires

Answer

Work in wet conditions

Question 53

What is the main function of a capacitor in an electrical circuit?

Accepted Answer

To store electrical energy in an electric field

Answer

To regulate the voltage level

Answer

To conduct current

Answer

To protect the circuit from overloads

Question 54

Which of the following is a type of electrical wiring method?

Accepted Answer

Conduit

Answer

Transformer

Answer

Resistor

Answer

Fuse

Question 55

What is the main difference between AC and DC electricity?

Accepted Answer

AC alternates current direction periodically, while DC flows in one direction

Answer

AC is more dangerous than DC

Answer

AC is used in homes, while DC is used in cars