Los Angeles Department of Water and Power (LADWP)
Electrical Craft Helper (Class Code 3799) Exam | Latest
Verified Questions and Detailed Answers
OVERVIEW DESCRIPTION:
This Comprehensive set of multiple choice questions is designed for the Los Angeles
Department of Water and Power (LADWP) Electrical Craft Helper (Class Code 3799)
examination, an entry-level test that evaluates foundational knowledge and aptitude for
assisting electricians and line workers in utility operations. The exam uses a multiple-
choice format and covers fundamental electrical theory, including basic AC/DC concepts,
Ohm’s Law, power formulas, and the use of meters such as voltmeters, ammeters,
ohmmeters, and meggers. It also assesses knowledge of common hand and power tools,
utility knots, workplace safety procedures including personal protective equipment and
lockout/tagout, basic arithmetic, wire sizing, technical reading comprehension, and
mechanical and spatial reasoning. The content is designed to measure practical, job-
relevant skills and safety awareness needed for entry-level electrical craft support work.
QUESTION 1
What is the unit of electrical current?
A. Volt
B. Ohm
C. Ampere
D. Watt
CORRECT ANSWER: C
EXPERT RATIONALE: Current is the flow of electric charge and is measured in amperes.
Voltage, resistance, and power use different units.
QUESTION 2
Ohm's Law states that voltage equals:
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A. Current × resistance
B. Current ÷ resistance
C. Power × current
D. Resistance ÷ current
CORRECT ANSWER: A
EXPERT RATIONALE: Ohm's Law is V = I × R, where V is voltage, I is current, and R is
resistance. This relationship is fundamental for analyzing basic circuits.
QUESTION 3
If a circuit has 120 volts applied and a resistance of 30 ohms, the current is:
A. 0.25 A
B. 4 A
C. 30 A
D. 3600 A
CORRECT ANSWER: B
EXPERT RATIONALE: Using Ohm's Law, I = V ÷ R = 120 ÷ 30 = 4 amperes. This is a direct
application of the formula.
QUESTION 4
Electrical power in a DC circuit is calculated as:
A. Voltage × current
B. Voltage ÷ current
C. Current × resistance
D. Voltage × resistance
CORRECT ANSWER: A
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EXPERT RATIONALE: Power in watts equals voltage times current, P = V × I. Other forms
apply in AC circuits with power factor.
QUESTION 5
A circuit draws 10 A at 120 V. The power consumed is:
A. 12 W
B. 120 W
C. 1200 W
D. 12000 W
CORRECT ANSWER: C
EXPERT RATIONALE: Power is P = V × I = 120 × 10 = 1200 watts. This basic power
calculation is common in electrical work.
QUESTION 6
An ohmmeter is used to measure:
A. Voltage
B. Current
C. Resistance
D. Power
CORRECT ANSWER: C
EXPERT RATIONALE: An ohmmeter measures electrical resistance in ohms. It must be
used on de-energized circuits to avoid damage and injury.
QUESTION 7
A voltmeter should be connected in:
A. Series with the load
B. Parallel with the load
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C. Series with the source only
D. Any configuration
CORRECT ANSWER: B
EXPERT RATIONALE: Voltmeters measure potential difference and are connected in
parallel with the component. Ammeters are connected in series.
QUESTION 8
An ammeter is connected in a circuit:
A. In parallel
B. In series
C. Across the source
D. Only after the load
CORRECT ANSWER: B
EXPERT RATIONALE: Ammeters measure current flow and must be placed in series so
the current passes through the meter. A parallel connection would create a short circuit.
QUESTION 9
Which instrument is used to test insulation resistance?
A. Voltmeter
B. Ammeter
C. Megger
D. Ohmmeter
CORRECT ANSWER: C
EXPERT RATIONALE: A megger applies a high test voltage to measure insulation
resistance in megohms. It detects insulation breakdown or moisture.