LADWP ELECTRICAL CRAFT HELPER BASIC
ELECTRICITY PRACTICE EXAM WITH
ACTUAL QUESTIONS AND VERIFIED
ANSWERS, PLUS EXPLAINED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED 100% PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
Question 1
A 120-volt single-phase circuit supplies a resistive load drawing 10
amperes. Using Ohm’s law, what is the resistance of the load?
A. 0.83 Ω
B. 12 Ω
C. 120 Ω
D. 1,200 Ω
Answer: B. 12 Ω
Rationale: Ohm’s law states that R = V ÷ I. Therefore, R = 120 V ÷ 10
A = 12 Ω. Resistance is the opposition to current flow, measured in
ohms.
Question 2
Which electrical quantity is measured in amperes?
A. Voltage
B. Resistance
C. Power
D. Current
Answer: D. Current
1
,Rationale: Electric current is the rate at which electrical charge flows
through a circuit and is measured in amperes (A). Voltage is measured
in volts, resistance in ohms, and power in watts.
Question 3
An electrical worker measures 240 volts across a 30-ohm resistive load.
Approximately how much current should flow through the load?
A. 8 A
B. 0.125 A
C. 270 A
D. 7,200 A
Answer: A. 8 A
Rationale: Ohm’s law gives I = V ÷ R. Thus, I = 240 ÷ 30 = 8 amperes.
This assumes a purely resistive load and ideal conditions.
Question 4
What is the primary purpose of a circuit breaker in an electrical circuit?
A. Increase circuit voltage
B. Store electrical energy
C. Interrupt current when an overcurrent condition occurs
D. Convert AC power to DC power
Answer: C. Interrupt current when an overcurrent condition occurs
Rationale: A circuit breaker is an overcurrent protective device
designed to open the circuit when current exceeds its intended safe
level. It helps protect conductors and equipment from damage caused
by excessive current.
2
,Question 5
Which material is generally considered a good electrical conductor?
A. Copper
B. Glass
C. Rubber
D. Dry wood
Answer: A. Copper
Rationale: Copper has relatively low electrical resistance and is widely
used for electrical conductors. Rubber, glass, and dry wood generally
provide much greater resistance to current flow.
Question 6
A 120-volt heater has a resistance of 24 ohms. What power does it
consume under steady-state resistive operation?
A. 5 W
B. 120 W
C. 600 W
D. 2,880 W
Answer: C. 600 W
Rationale: Power can be calculated using P = V² ÷ R. Therefore, P =
120² ÷ 24 = 14,400 ÷ 24 = 600 watts.
Question 7
In a series circuit containing three resistors, which statement is correct?
A. Voltage is always identical across every resistor
B. The same current flows through each resistor
3
, C. Total resistance is always less than the smallest resistor
D. Current divides equally between all resistors
Answer: B. The same current flows through each resistor
Rationale: In a series circuit there is only one path for current, so the
same current flows through every series component. The total
resistance equals the sum of the individual resistances.
Question 8
Two resistors of 10 Ω and 20 Ω are connected in series. What is their
total resistance?
A. 0.5 Ω
B. 10 Ω
C. 20 Ω
D. 30 Ω
Answer: D. 30 Ω
Rationale: Series resistances add directly: RT = R1 + R2 = 10 Ω + 20
Ω = 30 Ω.
Question 9
Two identical 20-ohm resistors are connected in parallel. What is the
equivalent resistance?
A. 10 Ω
B. 20 Ω
C. 40 Ω
D. 400 Ω
Answer: A. 10 Ω
4
ELECTRICITY PRACTICE EXAM WITH
ACTUAL QUESTIONS AND VERIFIED
ANSWERS, PLUS EXPLAINED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED 100% PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
Question 1
A 120-volt single-phase circuit supplies a resistive load drawing 10
amperes. Using Ohm’s law, what is the resistance of the load?
A. 0.83 Ω
B. 12 Ω
C. 120 Ω
D. 1,200 Ω
Answer: B. 12 Ω
Rationale: Ohm’s law states that R = V ÷ I. Therefore, R = 120 V ÷ 10
A = 12 Ω. Resistance is the opposition to current flow, measured in
ohms.
Question 2
Which electrical quantity is measured in amperes?
A. Voltage
B. Resistance
C. Power
D. Current
Answer: D. Current
1
,Rationale: Electric current is the rate at which electrical charge flows
through a circuit and is measured in amperes (A). Voltage is measured
in volts, resistance in ohms, and power in watts.
Question 3
An electrical worker measures 240 volts across a 30-ohm resistive load.
Approximately how much current should flow through the load?
A. 8 A
B. 0.125 A
C. 270 A
D. 7,200 A
Answer: A. 8 A
Rationale: Ohm’s law gives I = V ÷ R. Thus, I = 240 ÷ 30 = 8 amperes.
This assumes a purely resistive load and ideal conditions.
Question 4
What is the primary purpose of a circuit breaker in an electrical circuit?
A. Increase circuit voltage
B. Store electrical energy
C. Interrupt current when an overcurrent condition occurs
D. Convert AC power to DC power
Answer: C. Interrupt current when an overcurrent condition occurs
Rationale: A circuit breaker is an overcurrent protective device
designed to open the circuit when current exceeds its intended safe
level. It helps protect conductors and equipment from damage caused
by excessive current.
2
,Question 5
Which material is generally considered a good electrical conductor?
A. Copper
B. Glass
C. Rubber
D. Dry wood
Answer: A. Copper
Rationale: Copper has relatively low electrical resistance and is widely
used for electrical conductors. Rubber, glass, and dry wood generally
provide much greater resistance to current flow.
Question 6
A 120-volt heater has a resistance of 24 ohms. What power does it
consume under steady-state resistive operation?
A. 5 W
B. 120 W
C. 600 W
D. 2,880 W
Answer: C. 600 W
Rationale: Power can be calculated using P = V² ÷ R. Therefore, P =
120² ÷ 24 = 14,400 ÷ 24 = 600 watts.
Question 7
In a series circuit containing three resistors, which statement is correct?
A. Voltage is always identical across every resistor
B. The same current flows through each resistor
3
, C. Total resistance is always less than the smallest resistor
D. Current divides equally between all resistors
Answer: B. The same current flows through each resistor
Rationale: In a series circuit there is only one path for current, so the
same current flows through every series component. The total
resistance equals the sum of the individual resistances.
Question 8
Two resistors of 10 Ω and 20 Ω are connected in series. What is their
total resistance?
A. 0.5 Ω
B. 10 Ω
C. 20 Ω
D. 30 Ω
Answer: D. 30 Ω
Rationale: Series resistances add directly: RT = R1 + R2 = 10 Ω + 20
Ω = 30 Ω.
Question 9
Two identical 20-ohm resistors are connected in parallel. What is the
equivalent resistance?
A. 10 Ω
B. 20 Ω
C. 40 Ω
D. 400 Ω
Answer: A. 10 Ω
4
