CFESA Certification Exam 2026/2027 | Complete
300 Practice Questions, Correct Answers &
Detailed Rationales | Electrical, Gas, Steam &
Refrigeration
Electrical (Questions 1–75)
1. What is Ohm’s law?
A) V = I / R
B) V = I × R
C) I = V × R
D) R = V × I
Answer: B
Rationale: Voltage equals current times resistance. This is the foundation of electrical troubleshooting.
2. What is the unit of electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: C
Rationale: Resistance is measured in ohms (Ω).
3. What is the unit of electrical current?
A) Volt
,B) Ampere
C) Ohm
D) Watt
Answer: B
Rationale: Current is measured in amperes (amps).
4. What is the unit of electrical voltage?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: A
Rationale: Voltage is electrical potential difference, measured in volts.
5. Which meter measures current without breaking the circuit?
A) Voltmeter
B) Clamp-on ammeter
C) Ohmmeter
D) Megohmmeter
Answer: B
Rationale: Clamp meters sense magnetic field around a conductor.
6. How is a voltmeter connected?
A) In series
B) In parallel
C) In series-parallel
D) Across a capacitor only
Answer: B
,Rationale: Voltmeters measure potential difference across two points.
7. How is an ammeter connected?
A) In series
B) In parallel
C) Across a resistor
D) Across a switch
Answer: A
Rationale: Ammeters must carry the circuit current, so they are wired in series.
8. Before using an ohmmeter, you must:
A) Energize the circuit
B) De-energize the circuit
C) Short the leads
D) Set to DC volts
Answer: B
Rationale: Ohmmeters supply their own voltage; external power damages the meter.
9. Continuity mode on a multimeter will:
A) Measure voltage
B) Beep if the circuit is complete
C) Measure capacitance
D) Measure temperature
Answer: B
Rationale: Continuity checks for closed paths and opens.
10. What is the purpose of a fuse?
, A) Increase voltage
B) Protect circuit from overcurrent
C) Store energy
D) Rectify AC
Answer: B
Rationale: Fuses melt and open the circuit when current exceeds rating.
11. What is the purpose of a circuit breaker?
A) Protect circuit from overcurrent
B) Increase resistance
C) Store charge
D) Convert AC to DC
Answer: A
Rationale: Breakers trip on overcurrent and can be reset.
12. Which wire color is typically equipment ground?
A) Black
B) White
C) Green
D) Red
Answer: C
Rationale: Green or green/yellow is ground.
13. Which wire color is typically neutral?
A) Black
B) White
C) Green
D) Red
300 Practice Questions, Correct Answers &
Detailed Rationales | Electrical, Gas, Steam &
Refrigeration
Electrical (Questions 1–75)
1. What is Ohm’s law?
A) V = I / R
B) V = I × R
C) I = V × R
D) R = V × I
Answer: B
Rationale: Voltage equals current times resistance. This is the foundation of electrical troubleshooting.
2. What is the unit of electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: C
Rationale: Resistance is measured in ohms (Ω).
3. What is the unit of electrical current?
A) Volt
,B) Ampere
C) Ohm
D) Watt
Answer: B
Rationale: Current is measured in amperes (amps).
4. What is the unit of electrical voltage?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: A
Rationale: Voltage is electrical potential difference, measured in volts.
5. Which meter measures current without breaking the circuit?
A) Voltmeter
B) Clamp-on ammeter
C) Ohmmeter
D) Megohmmeter
Answer: B
Rationale: Clamp meters sense magnetic field around a conductor.
6. How is a voltmeter connected?
A) In series
B) In parallel
C) In series-parallel
D) Across a capacitor only
Answer: B
,Rationale: Voltmeters measure potential difference across two points.
7. How is an ammeter connected?
A) In series
B) In parallel
C) Across a resistor
D) Across a switch
Answer: A
Rationale: Ammeters must carry the circuit current, so they are wired in series.
8. Before using an ohmmeter, you must:
A) Energize the circuit
B) De-energize the circuit
C) Short the leads
D) Set to DC volts
Answer: B
Rationale: Ohmmeters supply their own voltage; external power damages the meter.
9. Continuity mode on a multimeter will:
A) Measure voltage
B) Beep if the circuit is complete
C) Measure capacitance
D) Measure temperature
Answer: B
Rationale: Continuity checks for closed paths and opens.
10. What is the purpose of a fuse?
, A) Increase voltage
B) Protect circuit from overcurrent
C) Store energy
D) Rectify AC
Answer: B
Rationale: Fuses melt and open the circuit when current exceeds rating.
11. What is the purpose of a circuit breaker?
A) Protect circuit from overcurrent
B) Increase resistance
C) Store charge
D) Convert AC to DC
Answer: A
Rationale: Breakers trip on overcurrent and can be reset.
12. Which wire color is typically equipment ground?
A) Black
B) White
C) Green
D) Red
Answer: C
Rationale: Green or green/yellow is ground.
13. Which wire color is typically neutral?
A) Black
B) White
C) Green
D) Red
