Electrician Certification Exam Practice
Questions.
1. What is the standard unit used to measure electrical current?
A. Volt
B. Watt
C. Ampere (Amp)
D. Ohm
Correct Answer: C. Ampere (Amp)
Rationale: Electrical current is measured in amperes (amps), which indicate the flow of electric
charge through a conductor.
2. What is the standard unit used to measure electrical voltage?
A. Ampere
B. Volt
C. Watt
D. Ohm
Correct Answer: B. Volt
Rationale: Voltage is the electrical potential difference that drives current through a circuit and
is measured in volts.
3. Which unit measures electrical resistance?
A. Ampere
B. Watt
C. Ohm
D. Volt
Correct Answer: C. Ohm
Rationale: Resistance opposes the flow of electrical current and is measured in ohms (Ω).
,4. According to Ohm's Law, current (I) equals:
A. Voltage × Resistance
B. Voltage ÷ Resistance
C. Resistance ÷ Voltage
D. Power ÷ Voltage
Correct Answer: B. Voltage ÷ Resistance
Rationale: Ohm's Law states I = V ÷ R, where current equals voltage divided by resistance.
5. What is the unit of electrical power?
A. Volt
B. Ampere
C. Watt
D. Ohm
Correct Answer: C. Watt
Rationale: Power is measured in watts and is calculated using P = V × I.
6. Which material is commonly used as an electrical conductor?
A. Rubber
B. Plastic
C. Copper
D. Glass
Correct Answer: C. Copper
Rationale: Copper has excellent electrical conductivity and is widely used for electrical wiring.
,7. Which material is commonly used as an electrical insulator?
A. Aluminum
B. Copper
C. Plastic
D. Silver
Correct Answer: C. Plastic
Rationale: Plastic resists electrical current and protects users from electrical shock.
8. What is the primary purpose of a circuit breaker?
A. Increase voltage
B. Reduce resistance
C. Protect the circuit from overloads and short circuits
D. Generate electricity
Correct Answer: C. Protect the circuit from overloads and short circuits
Rationale: Circuit breakers automatically interrupt current when unsafe conditions occur.
9. Which electrical fault occurs when current flows through an unintended low-
resistance path?
A. Open circuit
B. Short circuit
C. Grounding
D. Voltage drop
Correct Answer: B. Short circuit
Rationale: Short circuits can cause excessive current and create fire or shock hazards.
10. What color is commonly used to identify the equipment grounding conductor
in North America?
A. Red
B. Black
, C. Green or Bare Copper
D. Blue
Correct Answer: C. Green or Bare Copper
Rationale: Green insulation or bare copper identifies the equipment grounding conductor.
11. What is the purpose of grounding an electrical system?
A. Increase electrical load
B. Provide a safe path for fault current
C. Reduce wire size
D. Increase voltage
Correct Answer: B. Provide a safe path for fault current
Rationale: Grounding helps reduce the risk of electric shock and assists protective devices in
operating during faults.
12. Which instrument is used to measure electrical voltage?
A. Ammeter
B. Voltmeter
C. Ohmmeter
D. Clamp Meter
Correct Answer: B. Voltmeter
Rationale: A voltmeter measures the electrical potential difference between two points in a
circuit.
13. Which instrument measures electrical current without disconnecting the
conductor?
A. Clamp Meter
B. Screwdriver
C. Megohmmeter
D. Continuity Tester
Correct Answer: A. Clamp Meter
Questions.
1. What is the standard unit used to measure electrical current?
A. Volt
B. Watt
C. Ampere (Amp)
D. Ohm
Correct Answer: C. Ampere (Amp)
Rationale: Electrical current is measured in amperes (amps), which indicate the flow of electric
charge through a conductor.
2. What is the standard unit used to measure electrical voltage?
A. Ampere
B. Volt
C. Watt
D. Ohm
Correct Answer: B. Volt
Rationale: Voltage is the electrical potential difference that drives current through a circuit and
is measured in volts.
3. Which unit measures electrical resistance?
A. Ampere
B. Watt
C. Ohm
D. Volt
Correct Answer: C. Ohm
Rationale: Resistance opposes the flow of electrical current and is measured in ohms (Ω).
,4. According to Ohm's Law, current (I) equals:
A. Voltage × Resistance
B. Voltage ÷ Resistance
C. Resistance ÷ Voltage
D. Power ÷ Voltage
Correct Answer: B. Voltage ÷ Resistance
Rationale: Ohm's Law states I = V ÷ R, where current equals voltage divided by resistance.
5. What is the unit of electrical power?
A. Volt
B. Ampere
C. Watt
D. Ohm
Correct Answer: C. Watt
Rationale: Power is measured in watts and is calculated using P = V × I.
6. Which material is commonly used as an electrical conductor?
A. Rubber
B. Plastic
C. Copper
D. Glass
Correct Answer: C. Copper
Rationale: Copper has excellent electrical conductivity and is widely used for electrical wiring.
,7. Which material is commonly used as an electrical insulator?
A. Aluminum
B. Copper
C. Plastic
D. Silver
Correct Answer: C. Plastic
Rationale: Plastic resists electrical current and protects users from electrical shock.
8. What is the primary purpose of a circuit breaker?
A. Increase voltage
B. Reduce resistance
C. Protect the circuit from overloads and short circuits
D. Generate electricity
Correct Answer: C. Protect the circuit from overloads and short circuits
Rationale: Circuit breakers automatically interrupt current when unsafe conditions occur.
9. Which electrical fault occurs when current flows through an unintended low-
resistance path?
A. Open circuit
B. Short circuit
C. Grounding
D. Voltage drop
Correct Answer: B. Short circuit
Rationale: Short circuits can cause excessive current and create fire or shock hazards.
10. What color is commonly used to identify the equipment grounding conductor
in North America?
A. Red
B. Black
, C. Green or Bare Copper
D. Blue
Correct Answer: C. Green or Bare Copper
Rationale: Green insulation or bare copper identifies the equipment grounding conductor.
11. What is the purpose of grounding an electrical system?
A. Increase electrical load
B. Provide a safe path for fault current
C. Reduce wire size
D. Increase voltage
Correct Answer: B. Provide a safe path for fault current
Rationale: Grounding helps reduce the risk of electric shock and assists protective devices in
operating during faults.
12. Which instrument is used to measure electrical voltage?
A. Ammeter
B. Voltmeter
C. Ohmmeter
D. Clamp Meter
Correct Answer: B. Voltmeter
Rationale: A voltmeter measures the electrical potential difference between two points in a
circuit.
13. Which instrument measures electrical current without disconnecting the
conductor?
A. Clamp Meter
B. Screwdriver
C. Megohmmeter
D. Continuity Tester
Correct Answer: A. Clamp Meter
