LADWP ELECTRICAL CRAFT HELPER EXAM – PRACTICE
QUESTIONS, VERIFIED ANSWERS & DETAILED RATIONALES
1. What is the total current flowing in a 120V circuit that
powers two 60-watt light bulbs connected in parallel?
• A) 0.5 Amps
• B) 1.0 Amp
• C) 2.0 Amps
• D) 120 Amps
Correct Answer: B) 1.0 Amp
Rationale: Total power consumption is $60\text{W} + 60\text{W} =
120\text{W}$. Using the power formula ($P = V \times I$), we re-arrange to
solve for current: $I = \frac{P}{V} = \frac{120\text{W}}{120\text{V}} = 1.0\text{
Amp}$.
2. How many full 120-foot lengths of wire can be cut from five
500-foot reels?
• A) 16
• B) 18
• C) 20
• D) 22
Correct Answer: C) 20
Rationale: Total available length is $5 \times 500\text{ ft} = 2,500\text{ ft}$.
Dividing total length by the cut size: $2,500 \div 120 = 20.83$. Only 20
complete 120-foot lengths can be cut without splicing.
3. According to Ohm’s Law, if resistance in a fixed-voltage
circuit is doubled, what happens to the current?
• A) The current doubles.
• B) The current quadruples.
• C) The current is halved.
• D) The current remains unchanged.
Correct Answer: C) The current is halved.
Rationale: Ohm's Law states $I = \frac{V}{R}$. Current and resistance are
inversely proportional when voltage is constant; doubling resistance cuts
current by half.
, 4. When measuring dimensions near high-voltage energized
equipment in a substation, which tool is safest?
• A) A steel tape measure
• B) A wooden folding rule
• C) A cloth tape reinforced with metallic threads
• D) A steel surveying chain
Correct Answer: B) A wooden folding rule
Rationale: Metal tapes conduct electricity and create lethal flashover
hazards near live equipment. Non-conductive wooden rules or fiberglass
tapes are required.
5. Which knot forms a secure, non-slip loop at the end of a rope
used for hoisting tools or equipment?
• A) Square Knot
• B) Clove Hitch
• C) Bowline
• D) Half Hitch
Correct Answer: C) Bowline
Rationale: The Bowline creates a fixed loop that will not slip or jam under
heavy loads and stays easy to untie after use.
6. Under standard OSHA and utility safety rules, when must
Personal Protective Equipment (PPE) be inspected?
• A) At the end of each shift
• B) Before each use
• C) Once a week during tailgate meetings
• D) Monthly by a supervisor
Correct Answer: B) Before each use
Rationale: PPE must be inspected prior to every use to detect cracks, wear,
or damage before exposing workers to hazards.
7. What is the correct setback ratio when placing an extension
ladder against a wall?
• A) 1:1 rule
• B) 2:1 rule
• C) 4:1 rule
• D) 6:1 rule
QUESTIONS, VERIFIED ANSWERS & DETAILED RATIONALES
1. What is the total current flowing in a 120V circuit that
powers two 60-watt light bulbs connected in parallel?
• A) 0.5 Amps
• B) 1.0 Amp
• C) 2.0 Amps
• D) 120 Amps
Correct Answer: B) 1.0 Amp
Rationale: Total power consumption is $60\text{W} + 60\text{W} =
120\text{W}$. Using the power formula ($P = V \times I$), we re-arrange to
solve for current: $I = \frac{P}{V} = \frac{120\text{W}}{120\text{V}} = 1.0\text{
Amp}$.
2. How many full 120-foot lengths of wire can be cut from five
500-foot reels?
• A) 16
• B) 18
• C) 20
• D) 22
Correct Answer: C) 20
Rationale: Total available length is $5 \times 500\text{ ft} = 2,500\text{ ft}$.
Dividing total length by the cut size: $2,500 \div 120 = 20.83$. Only 20
complete 120-foot lengths can be cut without splicing.
3. According to Ohm’s Law, if resistance in a fixed-voltage
circuit is doubled, what happens to the current?
• A) The current doubles.
• B) The current quadruples.
• C) The current is halved.
• D) The current remains unchanged.
Correct Answer: C) The current is halved.
Rationale: Ohm's Law states $I = \frac{V}{R}$. Current and resistance are
inversely proportional when voltage is constant; doubling resistance cuts
current by half.
, 4. When measuring dimensions near high-voltage energized
equipment in a substation, which tool is safest?
• A) A steel tape measure
• B) A wooden folding rule
• C) A cloth tape reinforced with metallic threads
• D) A steel surveying chain
Correct Answer: B) A wooden folding rule
Rationale: Metal tapes conduct electricity and create lethal flashover
hazards near live equipment. Non-conductive wooden rules or fiberglass
tapes are required.
5. Which knot forms a secure, non-slip loop at the end of a rope
used for hoisting tools or equipment?
• A) Square Knot
• B) Clove Hitch
• C) Bowline
• D) Half Hitch
Correct Answer: C) Bowline
Rationale: The Bowline creates a fixed loop that will not slip or jam under
heavy loads and stays easy to untie after use.
6. Under standard OSHA and utility safety rules, when must
Personal Protective Equipment (PPE) be inspected?
• A) At the end of each shift
• B) Before each use
• C) Once a week during tailgate meetings
• D) Monthly by a supervisor
Correct Answer: B) Before each use
Rationale: PPE must be inspected prior to every use to detect cracks, wear,
or damage before exposing workers to hazards.
7. What is the correct setback ratio when placing an extension
ladder against a wall?
• A) 1:1 rule
• B) 2:1 rule
• C) 4:1 rule
• D) 6:1 rule
