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CWEA ELECTRICAL/INSTRUMENTATION TECHNOLOGIST
GRADE 1 EXAM QUESTIONS AND DETAILED ANSWERS
CWEA Electrical/Instrumentation Technologist Grade 1 Exam
Questions with Answers and Rationales
SECTION 1: ELECTRICAL THEORY AND FUNDAMENTALS (Questions 1–50)
1. Which of the following is the primary function of a current transformer (CT) in
electrical systems?
A) To increase voltage
B) To measure high currents safely
C) To store electrical energy
D) To protect against overvoltage
Answer: B
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.
2. 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
Answer: C
For two equal resistors in parallel, total resistance R_T = R ÷ 2 = 100 ÷ 2 = 50 ohms. For
unequal resistors: 1/R_T = 1/R₁ + 1/R₂.
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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
Answer: B
Line voltage is measured between any two line conductors in a three-phase system.
4. According to Ohm's Law, the current flowing through a conductor is equal to the
voltage across the conductor divided by which of the following quantities?
A) Power
B) Resistance
C) Capacitance
D) Inductance
Answer: B
Ohm's Law states that I = V/R, where I is current (amperes), V is voltage (volts), and R is
resistance (ohms).
5. What is the primary function of a step-down transformer?
A) To increase voltage
B) To decrease voltage
C) To convert AC to DC
D) To store electrical energy
Answer: B
A step-down transformer decreases voltage from the primary winding to the secondary
winding while increasing current proportionally.
6. In a series circuit, what is the total resistance?
A) The sum of all individual resistances
B) The product of all individual resistances
C) The reciprocal of the sum of reciprocals
D) Always equal to the largest resistance
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Answer: A
In a series circuit, total resistance is the sum of all individual resistances: R_T = R₁ + R₂ +
R₃ + ...
7. What is the formula for calculating power in a DC circuit?
A) P = V × I
B) P = V ÷ I
C) P = I ÷ V
D) P = V² × I
Answer: A
Power in a DC circuit is calculated as P = V × I, where P is power (watts), V is voltage
(volts), and I is current (amperes).
8. What is the unit of measurement for electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: C
Resistance is measured in ohms (Ω), named after Georg Simon Ohm.
9. What is the unit of measurement for electrical current?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: B
Current is measured in amperes (A), often called amps.
10. What is the unit of measurement for electrical power?
A) Volt
B) Ampere
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C) Ohm
D) Watt
Answer: D
Power is measured in watts (W), calculated as voltage multiplied by current.
11. In a parallel circuit, what is the total resistance?
A) The sum of all individual resistances
B) Always equal to the smallest resistance
C) Always less than the smallest individual resistance
D) Always greater than the largest resistance
Answer: C
In a parallel circuit, total resistance is always less than the smallest individual
resistance because there are multiple paths for current flow.
12. What is the formula for total resistance of two resistors in parallel?
A) R_T = R₁ + R₂
B) R_T = (R₁ × R₂) ÷ (R₁ + R₂)
C) R_T = R₁ ÷ R₂
D) R_T = 1 ÷ (R₁ + R₂)
Answer: B
For two resistors in parallel: R_T = (R₁ × R₂) ÷ (R₁ + R₂). This is often called the "product
over sum" formula.
13. What is the primary function of a capacitor in an electrical circuit?
A) To store electrical energy in an electric field
B) To store electrical energy in a magnetic field
C) To resist current flow
D) To convert AC to DC
Answer: A
A capacitor stores electrical energy in an electric field between two conductive plates
separated by a dielectric material.
CWEA ELECTRICAL/INSTRUMENTATION TECHNOLOGIST
GRADE 1 EXAM QUESTIONS AND DETAILED ANSWERS
CWEA Electrical/Instrumentation Technologist Grade 1 Exam
Questions with Answers and Rationales
SECTION 1: ELECTRICAL THEORY AND FUNDAMENTALS (Questions 1–50)
1. Which of the following is the primary function of a current transformer (CT) in
electrical systems?
A) To increase voltage
B) To measure high currents safely
C) To store electrical energy
D) To protect against overvoltage
Answer: B
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.
2. 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
Answer: C
For two equal resistors in parallel, total resistance R_T = R ÷ 2 = 100 ÷ 2 = 50 ohms. For
unequal resistors: 1/R_T = 1/R₁ + 1/R₂.
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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
Answer: B
Line voltage is measured between any two line conductors in a three-phase system.
4. According to Ohm's Law, the current flowing through a conductor is equal to the
voltage across the conductor divided by which of the following quantities?
A) Power
B) Resistance
C) Capacitance
D) Inductance
Answer: B
Ohm's Law states that I = V/R, where I is current (amperes), V is voltage (volts), and R is
resistance (ohms).
5. What is the primary function of a step-down transformer?
A) To increase voltage
B) To decrease voltage
C) To convert AC to DC
D) To store electrical energy
Answer: B
A step-down transformer decreases voltage from the primary winding to the secondary
winding while increasing current proportionally.
6. In a series circuit, what is the total resistance?
A) The sum of all individual resistances
B) The product of all individual resistances
C) The reciprocal of the sum of reciprocals
D) Always equal to the largest resistance
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Answer: A
In a series circuit, total resistance is the sum of all individual resistances: R_T = R₁ + R₂ +
R₃ + ...
7. What is the formula for calculating power in a DC circuit?
A) P = V × I
B) P = V ÷ I
C) P = I ÷ V
D) P = V² × I
Answer: A
Power in a DC circuit is calculated as P = V × I, where P is power (watts), V is voltage
(volts), and I is current (amperes).
8. What is the unit of measurement for electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: C
Resistance is measured in ohms (Ω), named after Georg Simon Ohm.
9. What is the unit of measurement for electrical current?
A) Volt
B) Ampere
C) Ohm
D) Watt
Answer: B
Current is measured in amperes (A), often called amps.
10. What is the unit of measurement for electrical power?
A) Volt
B) Ampere
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C) Ohm
D) Watt
Answer: D
Power is measured in watts (W), calculated as voltage multiplied by current.
11. In a parallel circuit, what is the total resistance?
A) The sum of all individual resistances
B) Always equal to the smallest resistance
C) Always less than the smallest individual resistance
D) Always greater than the largest resistance
Answer: C
In a parallel circuit, total resistance is always less than the smallest individual
resistance because there are multiple paths for current flow.
12. What is the formula for total resistance of two resistors in parallel?
A) R_T = R₁ + R₂
B) R_T = (R₁ × R₂) ÷ (R₁ + R₂)
C) R_T = R₁ ÷ R₂
D) R_T = 1 ÷ (R₁ + R₂)
Answer: B
For two resistors in parallel: R_T = (R₁ × R₂) ÷ (R₁ + R₂). This is often called the "product
over sum" formula.
13. What is the primary function of a capacitor in an electrical circuit?
A) To store electrical energy in an electric field
B) To store electrical energy in a magnetic field
C) To resist current flow
D) To convert AC to DC
Answer: A
A capacitor stores electrical energy in an electric field between two conductive plates
separated by a dielectric material.
