LADWP Electrical Craft Helper
Ultimate Exam
,Question 1: An Electrical Craft Helper (ECH) at a LADWP receiving station is
troubleshooting a 120V auxiliary heater circuit. Using a digital multimeter, the
helper measures a constant current draw of 10 Amperes. According to Ohm's Law
(Resistance = Voltage / Current), what is the total resistance of the heating
element?
A. 1,200 Ohms (calculated as 120V multiplied by 10A)
B. 110 Ohms (calculated as 120V minus 10A)
C. 0.08 Ohms (calculated as 10A divided by 120V)
D. 12 Ohms (calculated as 120V divided by 10A)
Answer: D. 12 Ohms (calculated as 120V divided by 10A)
Rationale: By Ohm's Law, Resistance R = V / I. Dividing 120 Volts by 10 Amperes yields
12 Ohms.
Question 2: What is the formula for electrical power (P in Watts) in a direct current
(DC) or resistive AC circuit when voltage (V) and current (I) are known? A LADWP
crew is installing a temporary 240V floodlight assembly consisting of two 1,200
Watt lamps connected in parallel. What is the total line current drawn?
A. 48 Amperes (calculated as 240V divided by 5A)
B. 10 Amperes (Total Power = 2,400W; I = P / V = 2, = 10A)
C. 20 Amperes (calculated as 2,400W divided by 120V)
D. 5 Amperes (calculated as 1,200W divided by 240V)
Answer: B. 10 Amperes (Total Power = 2,400W; I = P / V = 2, = 10A)
Rationale: Total power is 1,200W + 1,200W = 2,400W. Current I = P / V = 2,400W / 240V
= 10 Amperes.
,Question 3: An ECH is assigned to assist an Electrical Repairer with maintenance
on a 4,160V circuit breaker at a LADWP generating plant. Prior to opening the
breaker compartment door, what critical safety procedure MUST be verified first?
A. To signal to the dispatcher that the work is scheduled for completion within 2 hours
B. To prevent unauthorized workers from borrowing tools from the breaker cabinet
C. To bypass thermal overload relays during routine maintenance
D. To ensure the electrical energy source is completely isolated, locked in the safe
position, tagged, and tested for zero voltage before work begins
Answer: D. To ensure the electrical energy source is completely isolated, locked in
the safe position, tagged, and tested for zero voltage before work begins
Rationale: Lockout/Tagout (LOTO) establishes a positive zero-energy state, preventing
accidental re-energization while personnel perform work on electrical equipment.
Question 4: What specialized test instrument applies a high DC voltage (e.g., 500V
or 1,000V) to measure high-value insulation resistance in megohms on cables and
motor windings?
A. A Clamp-on Ammeter
B. A Megohmmeter (Megger)
C. An Oscilloscope
D. A Low-Voltage Continuity Beeper
Answer: B. A Megohmmeter (Megger)
Rationale: A Megohmmeter (commonly referred to as a Megger) generates a high DC
test voltage to measure insulation integrity in megohms.
, Question 5: A overhead line crew helper is rigging a heavy transformer to be
hoisted up a utility pole. The Line Mechanic instructs the helper to tie a non-slip
loop at the end of the winch line that will not jam under load. Which knot should the
helper tie?
A. Square knot (Reef knot)
B. Slip knot
C. Bowline knot
D. Overhand knot
Answer: C. Bowline knot
Rationale: The Bowline knot forms a reliable, non-slip loop at the end of a rope that holds
heavy weight without slipping and can be easily untied after strain.
Question 6: Under ASTM and OSHA standards for electrical protective equipment,
what is the maximum AC use voltage for Class 0 rubber insulating gloves?
A. Standard cotton canvas work gloves with nitrile grip dots
B. Class 2 Rubber Gloves (rated up to 17,000V AC max use voltage)
C. Class 00 Rubber Gloves (rated up to 500V AC max use voltage)
D. Class 0 Rubber Gloves (rated up to 1,000V AC max use voltage)
Answer: D. Class 0 Rubber Gloves (rated up to 1,000V AC max use voltage)
Rationale: Class 0 rubber insulating gloves are rated for a maximum use voltage of
1,000V AC (with Class 00 rated for 500V, Class 1 for 7,500V, and Class 2 for 17,000V).
Ultimate Exam
,Question 1: An Electrical Craft Helper (ECH) at a LADWP receiving station is
troubleshooting a 120V auxiliary heater circuit. Using a digital multimeter, the
helper measures a constant current draw of 10 Amperes. According to Ohm's Law
(Resistance = Voltage / Current), what is the total resistance of the heating
element?
A. 1,200 Ohms (calculated as 120V multiplied by 10A)
B. 110 Ohms (calculated as 120V minus 10A)
C. 0.08 Ohms (calculated as 10A divided by 120V)
D. 12 Ohms (calculated as 120V divided by 10A)
Answer: D. 12 Ohms (calculated as 120V divided by 10A)
Rationale: By Ohm's Law, Resistance R = V / I. Dividing 120 Volts by 10 Amperes yields
12 Ohms.
Question 2: What is the formula for electrical power (P in Watts) in a direct current
(DC) or resistive AC circuit when voltage (V) and current (I) are known? A LADWP
crew is installing a temporary 240V floodlight assembly consisting of two 1,200
Watt lamps connected in parallel. What is the total line current drawn?
A. 48 Amperes (calculated as 240V divided by 5A)
B. 10 Amperes (Total Power = 2,400W; I = P / V = 2, = 10A)
C. 20 Amperes (calculated as 2,400W divided by 120V)
D. 5 Amperes (calculated as 1,200W divided by 240V)
Answer: B. 10 Amperes (Total Power = 2,400W; I = P / V = 2, = 10A)
Rationale: Total power is 1,200W + 1,200W = 2,400W. Current I = P / V = 2,400W / 240V
= 10 Amperes.
,Question 3: An ECH is assigned to assist an Electrical Repairer with maintenance
on a 4,160V circuit breaker at a LADWP generating plant. Prior to opening the
breaker compartment door, what critical safety procedure MUST be verified first?
A. To signal to the dispatcher that the work is scheduled for completion within 2 hours
B. To prevent unauthorized workers from borrowing tools from the breaker cabinet
C. To bypass thermal overload relays during routine maintenance
D. To ensure the electrical energy source is completely isolated, locked in the safe
position, tagged, and tested for zero voltage before work begins
Answer: D. To ensure the electrical energy source is completely isolated, locked in
the safe position, tagged, and tested for zero voltage before work begins
Rationale: Lockout/Tagout (LOTO) establishes a positive zero-energy state, preventing
accidental re-energization while personnel perform work on electrical equipment.
Question 4: What specialized test instrument applies a high DC voltage (e.g., 500V
or 1,000V) to measure high-value insulation resistance in megohms on cables and
motor windings?
A. A Clamp-on Ammeter
B. A Megohmmeter (Megger)
C. An Oscilloscope
D. A Low-Voltage Continuity Beeper
Answer: B. A Megohmmeter (Megger)
Rationale: A Megohmmeter (commonly referred to as a Megger) generates a high DC
test voltage to measure insulation integrity in megohms.
, Question 5: A overhead line crew helper is rigging a heavy transformer to be
hoisted up a utility pole. The Line Mechanic instructs the helper to tie a non-slip
loop at the end of the winch line that will not jam under load. Which knot should the
helper tie?
A. Square knot (Reef knot)
B. Slip knot
C. Bowline knot
D. Overhand knot
Answer: C. Bowline knot
Rationale: The Bowline knot forms a reliable, non-slip loop at the end of a rope that holds
heavy weight without slipping and can be easily untied after strain.
Question 6: Under ASTM and OSHA standards for electrical protective equipment,
what is the maximum AC use voltage for Class 0 rubber insulating gloves?
A. Standard cotton canvas work gloves with nitrile grip dots
B. Class 2 Rubber Gloves (rated up to 17,000V AC max use voltage)
C. Class 00 Rubber Gloves (rated up to 500V AC max use voltage)
D. Class 0 Rubber Gloves (rated up to 1,000V AC max use voltage)
Answer: D. Class 0 Rubber Gloves (rated up to 1,000V AC max use voltage)
Rationale: Class 0 rubber insulating gloves are rated for a maximum use voltage of
1,000V AC (with Class 00 rated for 500V, Class 1 for 7,500V, and Class 2 for 17,000V).
