CWEA Electrical/Instrumentation Technologist Grade 1
Exam
150 Practice Questions & Detailed Solutions | 2026 Edition
SECTION 1: ELECTRICAL THEORY & FUNDAMENTALS
(Questions 1-40)
Question 1
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, the total resistance is RT = R ÷ 2 = 100 ÷ 2
= 50 ohms . The general formula for parallel resistance is 1/RT = 1/R₁ + 1/R₂.
Question 2
If 17.32 volts are applied across a resistance of 50 ohms, how much power is expended
in the resistor?
,A) 3.0 watts
B) 6.0 watts
C) 12.0 watts
D) 24.0 watts
Correct Answer: B
Rationale: Power is calculated using P = V² ÷ R = (17.32²) ÷ 50 = 300 ÷ 50 = 6.0 watts.
Power can also be calculated using P = I × E or P = I² × R .
Question 3
In a three-phase system, what is the voltage between any two line conductors called?
A) Phase voltage
B) Line voltage
C) Neutral voltage
D) Ground voltage
Correct Answer: B
Rationale: Line voltage is measured between any two line conductors in a three-phase
system, while phase voltage is measured from line to neutral .
Question 4
What is the voltage from phase to ground in a 480V transformer?
A) 120 volts
B) 208 volts
C) 240 volts
D) 277 volts
,Correct Answer: D
Rationale: In a 480V three-phase wye-connected system, the phase-to-ground voltage
is 277V. 480V ÷ √3 = 277V .
Question 5
What is the most common type of AC motor used at a treatment plant?
A) Wound rotor induction motor
B) Synchronous motor
C) Squirrel cage induction motor
D) Universal motor
Correct Answer: C
Rationale: The squirrel cage induction motor is the most common type of AC motor
used in treatment plants due to its simple construction, reliability, and low maintenance
requirements .
Question 6
A transformer has a primary voltage of 480V and a secondary voltage of 120V. What is
the turns ratio?
A) 2:1
B) 3:1
C) 4:1
D) 5:1
Correct Answer: C
, Rationale: The turns ratio is calculated by dividing the primary voltage by the secondary
voltage: 480 ÷ 120 = 4:1 .
Question 7
A transformer has a primary voltage of 120V and a secondary voltage of 12V with 20
amps on the secondary. What are the amps on the primary side?
A) 0.5 amps
B) 1 amp
C) 2 amps
D) 4 amps
Correct Answer: C
Rationale: Power remains constant (ignoring losses). Secondary power = 12V × 20A =
240 watts. Primary current = 240W ÷ 120V = 2 amps .
Question 8
What happens to wire resistance when temperature rises?
A) It decreases
B) It stays the same
C) It increases
D) It fluctuates randomly
Correct Answer: C
Rationale: For most metals (copper, aluminum), resistance increases as temperature
rises . This is important for understanding how operating temperatures affect electrical
equipment.
Exam
150 Practice Questions & Detailed Solutions | 2026 Edition
SECTION 1: ELECTRICAL THEORY & FUNDAMENTALS
(Questions 1-40)
Question 1
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, the total resistance is RT = R ÷ 2 = 100 ÷ 2
= 50 ohms . The general formula for parallel resistance is 1/RT = 1/R₁ + 1/R₂.
Question 2
If 17.32 volts are applied across a resistance of 50 ohms, how much power is expended
in the resistor?
,A) 3.0 watts
B) 6.0 watts
C) 12.0 watts
D) 24.0 watts
Correct Answer: B
Rationale: Power is calculated using P = V² ÷ R = (17.32²) ÷ 50 = 300 ÷ 50 = 6.0 watts.
Power can also be calculated using P = I × E or P = I² × R .
Question 3
In a three-phase system, what is the voltage between any two line conductors called?
A) Phase voltage
B) Line voltage
C) Neutral voltage
D) Ground voltage
Correct Answer: B
Rationale: Line voltage is measured between any two line conductors in a three-phase
system, while phase voltage is measured from line to neutral .
Question 4
What is the voltage from phase to ground in a 480V transformer?
A) 120 volts
B) 208 volts
C) 240 volts
D) 277 volts
,Correct Answer: D
Rationale: In a 480V three-phase wye-connected system, the phase-to-ground voltage
is 277V. 480V ÷ √3 = 277V .
Question 5
What is the most common type of AC motor used at a treatment plant?
A) Wound rotor induction motor
B) Synchronous motor
C) Squirrel cage induction motor
D) Universal motor
Correct Answer: C
Rationale: The squirrel cage induction motor is the most common type of AC motor
used in treatment plants due to its simple construction, reliability, and low maintenance
requirements .
Question 6
A transformer has a primary voltage of 480V and a secondary voltage of 120V. What is
the turns ratio?
A) 2:1
B) 3:1
C) 4:1
D) 5:1
Correct Answer: C
, Rationale: The turns ratio is calculated by dividing the primary voltage by the secondary
voltage: 480 ÷ 120 = 4:1 .
Question 7
A transformer has a primary voltage of 120V and a secondary voltage of 12V with 20
amps on the secondary. What are the amps on the primary side?
A) 0.5 amps
B) 1 amp
C) 2 amps
D) 4 amps
Correct Answer: C
Rationale: Power remains constant (ignoring losses). Secondary power = 12V × 20A =
240 watts. Primary current = 240W ÷ 120V = 2 amps .
Question 8
What happens to wire resistance when temperature rises?
A) It decreases
B) It stays the same
C) It increases
D) It fluctuates randomly
Correct Answer: C
Rationale: For most metals (copper, aluminum), resistance increases as temperature
rises . This is important for understanding how operating temperatures affect electrical
equipment.
