#1
Which wire color is typically used for the ground wire in electrical wiring?
Green
ExplanationGreen is commonly used for grounding due to safety standards.
#2
What is the standard voltage for household electrical systems in most countries?
220 volts
ExplanationMost countries utilize a standard voltage of 220 volts for household electrical systems.
#3
What is the purpose of polarization in electrical plugs and outlets?
To prevent electrical shocks
ExplanationPolarization in plugs and outlets helps prevent electrical shocks.
#4
What is the recommended minimum height for electrical outlets above the floor in residential buildings?
18 inches
ExplanationElectrical outlets are recommended to be installed at least 18 inches above the floor.
#5
What is the purpose of a shunt trip in a circuit breaker?
To trip the circuit breaker remotely
ExplanationShunt trips remotely trigger circuit breaker trips.
#6
What is the purpose of a lockout/tagout procedure in electrical safety?
To prevent unauthorized access to electrical equipment
ExplanationLockout/tagout prevents unauthorized access to electrical equipment for safety.
#7
What does GFCI stand for in electrical safety?
Ground Fault Circuit Interrupter
ExplanationGFCI stands for Ground Fault Circuit Interrupter, a device designed to protect against electric shock.
#8
Which of the following is NOT a recommended practice for electrical wiring safety?
Using electrical tape to cover exposed wires
ExplanationCovering exposed wires with electrical tape is not a recommended safety practice.
#9
What is the purpose of a junction box in electrical wiring?
To provide a secure enclosure for wire connections
ExplanationJunction boxes offer a safe enclosure for wire connections.
#10
Which type of circuit breaker automatically trips when it detects an overload or short circuit?
Double-pole breaker
ExplanationDouble-pole breakers trip upon detecting overloads or short circuits.
#11
What is the purpose of a ground wire in electrical wiring?
To provide a return path for fault currents
ExplanationGround wires offer a path for fault currents to prevent electric shock.
#12
Which of the following is NOT a type of electrical wire insulation?
Steel
ExplanationSteel is not typically used as insulation for electrical wires.
#13
What is the purpose of a surge protector in an electrical system?
To protect against sudden voltage spikes or surges
ExplanationSurge protectors safeguard electrical devices from voltage surges.
#14
What is the purpose of the National Electrical Code (NEC) in the United States?
To set standards for electrical installation and safety
ExplanationNEC establishes standards for electrical safety and installation in the US.
#15
Which type of electrical wire is typically used for long-distance transmission of electricity?
Aluminum wire
ExplanationAluminum wire is commonly used for long-distance electricity transmission.
#16
What is the purpose of an isolator switch in electrical systems?
To isolate a circuit from the power supply for maintenance
ExplanationIsolator switches disconnect circuits for maintenance.
#17
Which organization publishes the International Electrotechnical Commission (IEC) standards?
International Electrotechnical Commission (IEC)
ExplanationThe IEC is responsible for publishing international electrical standards.
#18
What does AFCI stand for in electrical safety?
Arc Fault Circuit Interrupter
ExplanationAFCI stands for Arc Fault Circuit Interrupter, used to prevent fires caused by electrical arcs.