1. Which of the following is the correct formula for calculating power in
an electrical circuit?
A) P = V × I
B) P = V / I
C) P = I / V
D) P = V² / R
Answer: A — Power equals voltage times current.
2. A circuit has a voltage of 240V and a current of 12A. What is the
power?
A) 28.8 W
B) 2.88 kW
C) 20 W
D) 288 W
Answer: B — P = 240 × 12 = 2,880 W = 2.88 kW.
3. Which device is used to protect an electrical circuit from damage
caused by overload or short circuit?
A) Switch
B) Breaker
C) Transformer
D) Conductor
Answer: B — Breakers are designed to interrupt overloads and faults.
4. Ohm's Law is expressed as:
A) V = R × P
B) V = I × R
C) I = P × V
D) R = V × I
Answer: B — Ohm’s Law: V = I × R.
5. In a 3-phase system, the line voltage is 480V. What is the phase
voltage in a wye configuration?
A) 277V
B) 480V
C) 240V
D) 138V
Answer: A — Line voltage ÷ √3 = 480 ÷ 1.732 ≈ 277V.
,Transformers
6. The function of a transformer is to:
A) Increase resistance
B) Convert DC to AC
C) Change voltage levels
D) Measure current
Answer: C — Transformers step voltage up or down.
7. A transformer with a 10:1 turns ratio steps down 2400V primary to:
A) 24V
B) 240V
C) 120V
D) 10V
Answer: B — 2400 ÷ 10 = 240V.
8. What is used in transformers to cool and insulate the windings?
A) Air
B) Water
C) Transformer oil
D) Freon
Answer: C — Oil is used for both insulation and cooling.
9. Which type of transformer connection is commonly used in
distribution systems?
A) Star-star
B) Delta-wye
C) Wye-delta
D) Open delta
Answer: B — Delta primary, wye secondary is typical.
10.Which transformer component provides protection from voltage
surges?
A) Insulating paper
B) Buchholz relay
C) Lightning arrester
D) Tap changer
Answer: C — Arresters divert surge voltage to ground.
Conductors & Wiring Methods
11.ACSR stands for:
A) Aluminum Copper Steel Resistance
B) Aluminum Conductor Steel Reinforced
, C) Alternating Copper Steel Rod
D) Aluminum Coated Steel Rod
Answer: B — ACSR is a common overhead conductor.
12.What is the main advantage of using ACSR conductors?
A) High resistance
B) Low cost
C) High tensile strength
D) Magnetic shielding
Answer: C — Steel core gives strength for long spans.
13.Underground conductors are typically insulated with:
A) Oil
B) PVC
C) XLP or EPR
D) Rubber
Answer: C — Cross-linked polyethylene (XLP) and ethylene propylene
rubber (EPR) are common.
14.Minimum burial depth for direct burial conductors under 600V is:
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Answer: D — NEC typically requires 24 inches for direct burial.
15.What color is used for neutral conductors in the NEC?
A) Red
B) Green
C) White or gray
D) Black
Answer: C — White or gray denotes neutral.
Poles and Structures
16.A guy wire is used to:
A) Carry current
B) Provide structural support
C) Protect from lightning
D) Conduct grounding
Answer: B — Guy wires stabilize poles.
17.Pole class defines:
A) Voltage capacity
B) Diameter
C) Strength
, D) Height
Answer: C — Pole class indicates load-bearing strength.
18.Typical spacing between transmission line poles is:
A) 25 ft
B) 50 ft
C) 100 ft
D) 300 ft or more
Answer: D — Depending on conductor and terrain.
19.What is installed at the top of a pole to support conductors?
A) Guy wire
B) Dead-end clamp
C) Crossarm
D) Handhole
Answer: C — Crossarms support multiple phases.
20.Which device prevents conductor sagging in long spans?
A) Insulator
B) Line tensioner
C) Spacer
D) Dead-end clamp
Answer: D — Dead-end clamps anchor tension.
Grounding & Overhead Systems
21.System grounding helps to:
A) Increase voltage
B) Prevent equipment overload
C) Stabilize voltage and improve safety
D) Enhance inductance
Answer: C — Grounding protects systems and personnel.
22.A ground rod should be driven to a minimum depth of:
A) 2 feet
B) 4 feet
C) 6 feet
D) 8 feet
Answer: D — NEC requires at least 8 feet.
23.The resistance of a ground system should not exceed:
A) 2 ohms
B) 10 ohms
C) 25 ohms
D) 100 ohms
Answer: C — Per NEC, 25 ohms or less is required.
an electrical circuit?
A) P = V × I
B) P = V / I
C) P = I / V
D) P = V² / R
Answer: A — Power equals voltage times current.
2. A circuit has a voltage of 240V and a current of 12A. What is the
power?
A) 28.8 W
B) 2.88 kW
C) 20 W
D) 288 W
Answer: B — P = 240 × 12 = 2,880 W = 2.88 kW.
3. Which device is used to protect an electrical circuit from damage
caused by overload or short circuit?
A) Switch
B) Breaker
C) Transformer
D) Conductor
Answer: B — Breakers are designed to interrupt overloads and faults.
4. Ohm's Law is expressed as:
A) V = R × P
B) V = I × R
C) I = P × V
D) R = V × I
Answer: B — Ohm’s Law: V = I × R.
5. In a 3-phase system, the line voltage is 480V. What is the phase
voltage in a wye configuration?
A) 277V
B) 480V
C) 240V
D) 138V
Answer: A — Line voltage ÷ √3 = 480 ÷ 1.732 ≈ 277V.
,Transformers
6. The function of a transformer is to:
A) Increase resistance
B) Convert DC to AC
C) Change voltage levels
D) Measure current
Answer: C — Transformers step voltage up or down.
7. A transformer with a 10:1 turns ratio steps down 2400V primary to:
A) 24V
B) 240V
C) 120V
D) 10V
Answer: B — 2400 ÷ 10 = 240V.
8. What is used in transformers to cool and insulate the windings?
A) Air
B) Water
C) Transformer oil
D) Freon
Answer: C — Oil is used for both insulation and cooling.
9. Which type of transformer connection is commonly used in
distribution systems?
A) Star-star
B) Delta-wye
C) Wye-delta
D) Open delta
Answer: B — Delta primary, wye secondary is typical.
10.Which transformer component provides protection from voltage
surges?
A) Insulating paper
B) Buchholz relay
C) Lightning arrester
D) Tap changer
Answer: C — Arresters divert surge voltage to ground.
Conductors & Wiring Methods
11.ACSR stands for:
A) Aluminum Copper Steel Resistance
B) Aluminum Conductor Steel Reinforced
, C) Alternating Copper Steel Rod
D) Aluminum Coated Steel Rod
Answer: B — ACSR is a common overhead conductor.
12.What is the main advantage of using ACSR conductors?
A) High resistance
B) Low cost
C) High tensile strength
D) Magnetic shielding
Answer: C — Steel core gives strength for long spans.
13.Underground conductors are typically insulated with:
A) Oil
B) PVC
C) XLP or EPR
D) Rubber
Answer: C — Cross-linked polyethylene (XLP) and ethylene propylene
rubber (EPR) are common.
14.Minimum burial depth for direct burial conductors under 600V is:
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Answer: D — NEC typically requires 24 inches for direct burial.
15.What color is used for neutral conductors in the NEC?
A) Red
B) Green
C) White or gray
D) Black
Answer: C — White or gray denotes neutral.
Poles and Structures
16.A guy wire is used to:
A) Carry current
B) Provide structural support
C) Protect from lightning
D) Conduct grounding
Answer: B — Guy wires stabilize poles.
17.Pole class defines:
A) Voltage capacity
B) Diameter
C) Strength
, D) Height
Answer: C — Pole class indicates load-bearing strength.
18.Typical spacing between transmission line poles is:
A) 25 ft
B) 50 ft
C) 100 ft
D) 300 ft or more
Answer: D — Depending on conductor and terrain.
19.What is installed at the top of a pole to support conductors?
A) Guy wire
B) Dead-end clamp
C) Crossarm
D) Handhole
Answer: C — Crossarms support multiple phases.
20.Which device prevents conductor sagging in long spans?
A) Insulator
B) Line tensioner
C) Spacer
D) Dead-end clamp
Answer: D — Dead-end clamps anchor tension.
Grounding & Overhead Systems
21.System grounding helps to:
A) Increase voltage
B) Prevent equipment overload
C) Stabilize voltage and improve safety
D) Enhance inductance
Answer: C — Grounding protects systems and personnel.
22.A ground rod should be driven to a minimum depth of:
A) 2 feet
B) 4 feet
C) 6 feet
D) 8 feet
Answer: D — NEC requires at least 8 feet.
23.The resistance of a ground system should not exceed:
A) 2 ohms
B) 10 ohms
C) 25 ohms
D) 100 ohms
Answer: C — Per NEC, 25 ohms or less is required.
