Exam Questions & Correct Answers
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1. What is the primary purpose of a lockout/tagout (LOTO) procedure?
A) To increase work speed
B) To prevent accidental energization of equipment
C) To save on electricity costs
D) To test voltage levels
Answer: B
Explanation: LOTO procedures are designed to ensure that equipment is properly shut off
and cannot be re-energized while maintenance is being performed, protecting workers
from hazardous energy.
2. Which of the following is the correct color for a grounded conductor (neutral) in
most AC systems?
A) Green
B) Black
C) Red
D) White or Gray
Answer: D
Explanation: In the National Electrical Code (NEC), white or gray is designated for
grounded conductors. Green is used for equipment grounding conductors, and black/red
are typically ungrounded conductors.
,3. What is Ohm's Law formula?
A) I = R / V
B) V = I * R
C) R = V * I
D) I = V * R
Answer: B
Explanation: Ohm's Law states that Voltage (V) equals Current (I) multiplied by Resistance
(R). This is a fundamental equation for understanding electrical circuits.
4. What type of meter is used to measure the resistance of a grounding electrode?
A) Megohmmeter
B) Clamp-on ammeter
C) Ground resistance tester
D) Wattmeter
Answer: C
Explanation: A ground resistance tester (often called a Megger, though that is a brand
name for insulation testers) specifically measures the resistance of a grounding system to
ensure it is low enough to safely dissipate fault currents.
5. What is the approximate voltage of a standard residential distribution line in
the US before stepping down to the customer?
A) 120 Volts
B) 240 Volts
C) 4,160 Volts or 12,000 Volts (Primary distribution)
D) 500,000 Volts
Answer: C
Explanation: Primary distribution lines operate at medium voltages like 4.16 kV or 12 kV.
They are stepped down by transformers to 120/240 Volts for residential use (secondary
voltage).
6. If a circuit has a voltage of 240V and a resistance of 40 Ohms, what is the
current?
,A) 6 Amps
B) 10 Amps
C) 600 Amps
D) 0.16 Amps
Answer: A
Explanation: Using I = V / R, 240V / 40Ω = 6 Amperes.
7. What is the purpose of an insulator on a power pole?
A) To conduct electricity
B) To support the conductor and prevent current leakage to ground
C) To increase the voltage
D) To step down voltage
Answer: B
Explanation: Insulators prevent the flow of current from the conductor to the pole or
ground. They are typically made of porcelain, glass, or polymer.
8. What is the minimum approach distance for an unqualified person from a 12 kV
overhead conductor?
A) 10 feet
B) 3 feet
C) 2 feet
D) 5 feet
Answer: A (OSHA standard for 12 kV is generally 10 feet for unqualified persons)
Explanation: OSHA regulations specify minimum approach distances (MAD). For
unqualified persons near lines up to 50 kV, the distance is typically 10 feet.
9. A transformer that steps down voltage from 7,200 V to 120 V has a turns ratio
of:
A) 60:1 (Primary:Secondary)
B) 1:60
C) 7200:1
D) 120:1
, Answer: A
Explanation: Turns ratio is proportional to voltage ratio. V_primary / V_secondary = 7,200
/ 120 = 60. So the primary has 60 times more turns than the secondary.
10. What does a "hot stick" allow a lineman to do?
A) Climb a wooden pole
B) Work on energized high-voltage lines while keeping the worker safe
C) Measure wind speed
D) Test oil levels in transformers
Answer: B
Explanation: Hot sticks are insulated tools used to manipulate equipment on energized
lines, protecting the lineman from electric shock.
11. Which of the following is a type of electrical fault characterized by a low-
impedance connection to ground?
A) Open circuit
B) Short circuit
C) Ground fault
D) High resistance joint
Answer: C
Explanation: A ground fault occurs when current unintentionally flows from an energized
conductor to the ground. It often involves low impedance to ground.
12. What is the function of a fuse?
A) To regulate voltage
B) To open a circuit during overcurrent conditions to protect equipment
C) To store electrical energy
D) To convert AC to DC
Answer: B
Explanation: A fuse contains a metal element that melts and opens the circuit when
current exceeds a specific rating for a certain amount of time, protecting downstream
components.