LADWP ELECTRIC DISTRIBUTION MECHANIC TRAINEE 150
ORIGINAL PRACTICE QUESTIONS • ANSWERS & RATIONALES |
2026/2027
Mechanical Principles
1. A longer wrench handle generally reduces the force needed to turn a
fastener because it increases what?
A. Electrical resistance
B. Torque arm
C. Thread pitch
D. Mass of the nut
Correct answer: B. Torque arm
Rationale: Torque equals force multiplied by the perpendicular lever arm.
2. Which simple machine forms the basis of a screw jack?
A. Pulley
B. Spring
C. Inclined plane
D. Wheel bearing
Correct answer: C. Inclined plane
Rationale: A screw is an inclined plane wrapped around a cylinder.
3. A fixed pulley ideally changes which aspect of pulling a load?
A. Total work required
B. Gravity
C. Direction of force
D. Load mass
Correct answer: C. Direction of force
Rationale: An ideal fixed pulley redirects force without mechanical
advantage.
4. In a frictionless two-part supporting rope system, the ideal
mechanical advantage is what?
A. 1
LADWP trainee • Independent practice guide • 2026/2027
, B. 8
C. 4
D. 2
Correct answer: D. 2
Rationale: Two rope segments share the supported load, halving ideal pulling
force.
5. Which condition makes a ladder more likely to slip?
A. Proper climbing angle
B. Footing on firm surface
C. Ladder secured
D. Base placed too close to the wall
Correct answer: D. Base placed too close to the wall
Rationale: A steep setup can destabilize the ladder; follow the prescribed
setup angle.
6. What is the principal function of a bearing?
A. Create a fuse
B. Increase conductor voltage
C. Reduce friction between moving surfaces
D. Stop all motion
Correct answer: C. Reduce friction between moving surfaces
Rationale: Bearings support movement while reducing friction.
7. A gear train with a small driving gear and larger driven gear
normally produces what?
A. No rotation
B. Greater energy output
C. Lower speed and greater output torque
D. Higher speed and lower torque
Correct answer: C. Lower speed and greater output torque
Rationale: A larger driven gear turns more slowly while providing more
torque, less losses.
LADWP trainee • Independent practice guide • 2026/2027
,8. For a load that may roll, what control should precede lifting?
A. Use a longer rope only
B. Raise it abruptly
C. Stand downhill of it
D. Chock or secure the load
Correct answer: D. Chock or secure the load
Rationale: Securing the load prevents uncontrolled movement.
9. Why is the center of gravity important when rigging?
A. It affects load stability during lifting
B. It determines wire gauge
C. It eliminates sling inspection
D. It changes the voltage
Correct answer: A. It affects load stability during lifting
Rationale: The hook line should align appropriately with load balance to
limit tipping.
10. What happens to a metal rod subjected to tension beyond its elastic
limit?
A. It becomes electrically insulated
B. Its mass vanishes
C. Permanent deformation may occur
D. Its length always decreases
Correct answer: C. Permanent deformation may occur
Rationale: Beyond elastic limits, a material may not return to its original
shape.
Hand and Power Tools
11. Which tool is best for accurately checking outside diameter?
A. Tin snips
B. Caliper
C. Hammer
D. Adjustable wrench
LADWP trainee • Independent practice guide • 2026/2027
, Correct answer: B. Caliper
Rationale: Calipers provide measured outside dimensions.
12. What is the safest action before replacing a drill bit?
A. Touch the rotating chuck
B. Increase the speed
C. Disconnect or isolate its power source
D. Hold the trigger
Correct answer: C. Disconnect or isolate its power source
Rationale: Prevent accidental start-up before adjustments.
13. Why should a damaged insulated hand tool be removed from
service?
A. It becomes more precise
B. Its insulation may not protect against contact hazards
C. It is easier to clean
D. It draws less current
Correct answer: B. Its insulation may not protect against contact
hazards
Rationale: Damaged insulation defeats the tool’s intended protection.
14. A torque wrench is mainly used to do what?
A. Detect gas
B. Apply a specified tightening torque
C. Measure amperage
D. Measure cable length
Correct answer: B. Apply a specified tightening torque
Rationale: Controlled torque helps achieve specified fastener tension.
15. When cutting material with a portable saw, what is essential?
A. Remove all guards
B. Hold the work in midair
C. Secure the workpiece
D. Use an unapproved blade
LADWP trainee • Independent practice guide • 2026/2027
ORIGINAL PRACTICE QUESTIONS • ANSWERS & RATIONALES |
2026/2027
Mechanical Principles
1. A longer wrench handle generally reduces the force needed to turn a
fastener because it increases what?
A. Electrical resistance
B. Torque arm
C. Thread pitch
D. Mass of the nut
Correct answer: B. Torque arm
Rationale: Torque equals force multiplied by the perpendicular lever arm.
2. Which simple machine forms the basis of a screw jack?
A. Pulley
B. Spring
C. Inclined plane
D. Wheel bearing
Correct answer: C. Inclined plane
Rationale: A screw is an inclined plane wrapped around a cylinder.
3. A fixed pulley ideally changes which aspect of pulling a load?
A. Total work required
B. Gravity
C. Direction of force
D. Load mass
Correct answer: C. Direction of force
Rationale: An ideal fixed pulley redirects force without mechanical
advantage.
4. In a frictionless two-part supporting rope system, the ideal
mechanical advantage is what?
A. 1
LADWP trainee • Independent practice guide • 2026/2027
, B. 8
C. 4
D. 2
Correct answer: D. 2
Rationale: Two rope segments share the supported load, halving ideal pulling
force.
5. Which condition makes a ladder more likely to slip?
A. Proper climbing angle
B. Footing on firm surface
C. Ladder secured
D. Base placed too close to the wall
Correct answer: D. Base placed too close to the wall
Rationale: A steep setup can destabilize the ladder; follow the prescribed
setup angle.
6. What is the principal function of a bearing?
A. Create a fuse
B. Increase conductor voltage
C. Reduce friction between moving surfaces
D. Stop all motion
Correct answer: C. Reduce friction between moving surfaces
Rationale: Bearings support movement while reducing friction.
7. A gear train with a small driving gear and larger driven gear
normally produces what?
A. No rotation
B. Greater energy output
C. Lower speed and greater output torque
D. Higher speed and lower torque
Correct answer: C. Lower speed and greater output torque
Rationale: A larger driven gear turns more slowly while providing more
torque, less losses.
LADWP trainee • Independent practice guide • 2026/2027
,8. For a load that may roll, what control should precede lifting?
A. Use a longer rope only
B. Raise it abruptly
C. Stand downhill of it
D. Chock or secure the load
Correct answer: D. Chock or secure the load
Rationale: Securing the load prevents uncontrolled movement.
9. Why is the center of gravity important when rigging?
A. It affects load stability during lifting
B. It determines wire gauge
C. It eliminates sling inspection
D. It changes the voltage
Correct answer: A. It affects load stability during lifting
Rationale: The hook line should align appropriately with load balance to
limit tipping.
10. What happens to a metal rod subjected to tension beyond its elastic
limit?
A. It becomes electrically insulated
B. Its mass vanishes
C. Permanent deformation may occur
D. Its length always decreases
Correct answer: C. Permanent deformation may occur
Rationale: Beyond elastic limits, a material may not return to its original
shape.
Hand and Power Tools
11. Which tool is best for accurately checking outside diameter?
A. Tin snips
B. Caliper
C. Hammer
D. Adjustable wrench
LADWP trainee • Independent practice guide • 2026/2027
, Correct answer: B. Caliper
Rationale: Calipers provide measured outside dimensions.
12. What is the safest action before replacing a drill bit?
A. Touch the rotating chuck
B. Increase the speed
C. Disconnect or isolate its power source
D. Hold the trigger
Correct answer: C. Disconnect or isolate its power source
Rationale: Prevent accidental start-up before adjustments.
13. Why should a damaged insulated hand tool be removed from
service?
A. It becomes more precise
B. Its insulation may not protect against contact hazards
C. It is easier to clean
D. It draws less current
Correct answer: B. Its insulation may not protect against contact
hazards
Rationale: Damaged insulation defeats the tool’s intended protection.
14. A torque wrench is mainly used to do what?
A. Detect gas
B. Apply a specified tightening torque
C. Measure amperage
D. Measure cable length
Correct answer: B. Apply a specified tightening torque
Rationale: Controlled torque helps achieve specified fastener tension.
15. When cutting material with a portable saw, what is essential?
A. Remove all guards
B. Hold the work in midair
C. Secure the workpiece
D. Use an unapproved blade
LADWP trainee • Independent practice guide • 2026/2027
