CWEA Electrical/Instrumentation
Technologist Grade 1 Exam 150 Practice
Questions & Detailed Solutions | 2026
Edition
Grade I: Basic Electrical & Instrumentation Principles
1. What is alternating current (AC)?
A. Current that flows only in one direction
B. Current that periodically reverses direction and changes magnitude
C. Current that is always constant
D. Current that only flows in a circuit when switched on
Correct Answer: B
Rationale: Alternating current (AC) is an electric current that periodically reverses
direction and changes its magnitude continuously with time. Most devices
connected to the electrical grid operate on AC .
2. What is the standard atmospheric pressure at sea level?
A. 10.5 psi
B. 12.0 psi
C. 14.7 psi
D. 18.2 psi
Correct Answer: C
,Rationale: 14.7 psi (pounds per square inch) is the accepted standard for
atmospheric pressure at sea level .
3. A 120-volt AC circuit draws a current of 5 amperes. Determine the power
consumption.
A. 60 watts
B. 120 watts
C. 4.8 watts
D. 600 watts
Correct Answer: D
Rationale: Power = Voltage × Current. 120V × 5A = 600 watts .
4. What color is typically used for the "neutral" wire in a standard 120V AC
circuit in the US?
A. Black
B. Red
C. White
D. Green
Correct Answer: C
Rationale: Per the NEC, white or gray conductors are reserved for the grounded
(neutral) wire. Black and red are typically used for "hot" conductors, and green for
grounding .
5. What is the total resistance of two 100-ohm resistors connected in parallel?
,A. 200 ohms
B. 100 ohms
C. 50 ohms
D. 25 ohms
Correct Answer: C
Rationale: For two equal resistors in parallel: R_total = R/n = 100/2 = 50 ohms.
Parallel resistance is always less than the smallest individual resistor .
6. What does the acronym "GFCI" stand for?
A. Grounded Flow Circuit Interrupter
B. Ground Fault Circuit Interrupter
C. General Fuse Circuit Indicator
D. Grounded Fuse Current Interrupter
Correct Answer: B
Rationale: A GFCI is a safety device that shuts off electric power when it detects
an imbalance between the outgoing and incoming current, protecting against
electrical shock .
7. A multimeter set to the Ohms setting should only be used on a circuit that is:
A. Energized with DC voltage
B. Energized with AC voltage
C. De-energized
D. Connected to a load
Correct Answer: C
, Rationale: Measuring resistance in an energized circuit can damage the meter
and provide inaccurate readings. The circuit must be de-energized before testing
resistance .
8. Which type of fire extinguisher is most appropriate for an electrical fire?
A. Class A
B. Class B
C. Class C
D. Class D
Correct Answer: C
Rationale: Class C fire extinguishers are specifically rated for fires involving
energized electrical equipment. Class A is for ordinary combustibles, Class B for
flammable liquids, and Class D for combustible metals .
9. The primary function of a current transformer (CT) in electrical systems is to:
A. Increase voltage
B. Measure high currents safely
C. Store electrical energy
D. Protect against overvoltage
Correct Answer: B
Rationale: A current transformer reduces high currents to a lower, measurable
value, allowing safe measurement and monitoring by instruments and protective
devices. CTs are essential for metering high-amperage circuits .
10. The purpose of an insulation resistance test is to:
Technologist Grade 1 Exam 150 Practice
Questions & Detailed Solutions | 2026
Edition
Grade I: Basic Electrical & Instrumentation Principles
1. What is alternating current (AC)?
A. Current that flows only in one direction
B. Current that periodically reverses direction and changes magnitude
C. Current that is always constant
D. Current that only flows in a circuit when switched on
Correct Answer: B
Rationale: Alternating current (AC) is an electric current that periodically reverses
direction and changes its magnitude continuously with time. Most devices
connected to the electrical grid operate on AC .
2. What is the standard atmospheric pressure at sea level?
A. 10.5 psi
B. 12.0 psi
C. 14.7 psi
D. 18.2 psi
Correct Answer: C
,Rationale: 14.7 psi (pounds per square inch) is the accepted standard for
atmospheric pressure at sea level .
3. A 120-volt AC circuit draws a current of 5 amperes. Determine the power
consumption.
A. 60 watts
B. 120 watts
C. 4.8 watts
D. 600 watts
Correct Answer: D
Rationale: Power = Voltage × Current. 120V × 5A = 600 watts .
4. What color is typically used for the "neutral" wire in a standard 120V AC
circuit in the US?
A. Black
B. Red
C. White
D. Green
Correct Answer: C
Rationale: Per the NEC, white or gray conductors are reserved for the grounded
(neutral) wire. Black and red are typically used for "hot" conductors, and green for
grounding .
5. What is the total resistance of two 100-ohm resistors connected in parallel?
,A. 200 ohms
B. 100 ohms
C. 50 ohms
D. 25 ohms
Correct Answer: C
Rationale: For two equal resistors in parallel: R_total = R/n = 100/2 = 50 ohms.
Parallel resistance is always less than the smallest individual resistor .
6. What does the acronym "GFCI" stand for?
A. Grounded Flow Circuit Interrupter
B. Ground Fault Circuit Interrupter
C. General Fuse Circuit Indicator
D. Grounded Fuse Current Interrupter
Correct Answer: B
Rationale: A GFCI is a safety device that shuts off electric power when it detects
an imbalance between the outgoing and incoming current, protecting against
electrical shock .
7. A multimeter set to the Ohms setting should only be used on a circuit that is:
A. Energized with DC voltage
B. Energized with AC voltage
C. De-energized
D. Connected to a load
Correct Answer: C
, Rationale: Measuring resistance in an energized circuit can damage the meter
and provide inaccurate readings. The circuit must be de-energized before testing
resistance .
8. Which type of fire extinguisher is most appropriate for an electrical fire?
A. Class A
B. Class B
C. Class C
D. Class D
Correct Answer: C
Rationale: Class C fire extinguishers are specifically rated for fires involving
energized electrical equipment. Class A is for ordinary combustibles, Class B for
flammable liquids, and Class D for combustible metals .
9. The primary function of a current transformer (CT) in electrical systems is to:
A. Increase voltage
B. Measure high currents safely
C. Store electrical energy
D. Protect against overvoltage
Correct Answer: B
Rationale: A current transformer reduces high currents to a lower, measurable
value, allowing safe measurement and monitoring by instruments and protective
devices. CTs are essential for metering high-amperage circuits .
10. The purpose of an insulation resistance test is to:
