LADWP Mechanical Helper Exam – Class 3771 | Latest
Update 2026/2027 | 200 Practice Questions & Detailed
Answers | Original Q&A with Rationales | Instant PDF
Download | A+ Graded
1. A mechanical helper is asked to remove a guard from a rotating machine so a journeylevel mechanic
can inspect the equipment. What should the helper do FIRST?
A) Remove the guard immediately to save time
B) Ask another helper to hold the guard
C) Verify that the equipment is properly isolated and deenergized before removing the guard
D) Loosen the guard bolts while the machine is still running
Answer: C
Rationale: Rotating equipment must be made safe before guards are removed. Isolation prevents
unexpected movement and exposure to moving parts .
2. A pipe must be cut and threaded for installation. Which sequence is most appropriate?
A) Thread the pipe, then cut it to length
B) Measure, cut, deburr, and then thread the pipe
C) Heat the pipe before measuring
D) Thread both ends before cutting
Answer: B
Rationale: Accurate measurement and cutting should precede threading. Deburring removes sharp
edges and helps produce a clean thread .
,3. A drill press begins producing a hole that is larger than the selected drill bit. What is the most likely
concern?
A) The workpiece is too clean
B) The drill press table is too low
C) The workpiece may not be secure or the drill may be damaged
D) The cutting speed is always too slow
Answer: C
Rationale: An improperly secured workpiece or damaged/bent tooling can cause the drill to wander and
produce an oversized hole .
4. Before operating a portable grinder, which condition requires immediate correction?
A) The workpiece is painted
B) The operator is wearing safety glasses
C) The grinding wheel has a visible crack
D) The grinder has a grounded plug
Answer: C
Rationale: A cracked grinding wheel can fail catastrophically during operation and must not be used .
,5. A mechanic tells a helper to hold a component while it is being drilled. The component begins shifting.
What is the safest response?
A) Hold it harder with one hand
B) Continue drilling at reduced speed
C) Stop and secure the component properly with a clamp or vise
D) Ask the mechanic to drill faster
Answer: C
Rationale: The workpiece should be secured with an appropriate clamp, vise, or fixture rather than held
by hand .
6. A wrench slips while loosening a fastener. Which action best reduces the likelihood of another slip?
A) Use a longer unrelated tool
B) Strike the wrench continuously
C) Use the correctly sized wrench fully engaged on the fastener
D) Hold the wrench at an angle
Answer: C
Rationale: Proper fit and full engagement provide better control and reduce slipping .
7. A helper is assisting with a suspended machine component. The load begins swinging. What should
the helper do?
A) Push the load while standing beneath it
, B) Grab the load with both hands
C) Keep clear of the suspended load and control the operation as directed
D) Stand underneath it to stabilize it
Answer: C
Rationale: Personnel should remain outside the danger zone of suspended loads. Loads should be
controlled using proper rigging and procedures .
8. A hoist is rated for 2,000 pounds. A component weighs approximately 2,100 pounds. What should the
helper do?
A) Lift it because the difference is small
B) Lift it slowly
C) Use two people to pull on it
D) Do not lift it with that hoist
Answer: D
Rationale: The rated capacity must not be exceeded. Appropriate lifting equipment with sufficient
capacity is required .
9. Which tool is generally most appropriate for gripping and turning a hexagonal fastener?
A) Pipe wrench
B) Box or socket wrench of the correct size
C) Slipjoint pliers
D) Adjustable wrench
Update 2026/2027 | 200 Practice Questions & Detailed
Answers | Original Q&A with Rationales | Instant PDF
Download | A+ Graded
1. A mechanical helper is asked to remove a guard from a rotating machine so a journeylevel mechanic
can inspect the equipment. What should the helper do FIRST?
A) Remove the guard immediately to save time
B) Ask another helper to hold the guard
C) Verify that the equipment is properly isolated and deenergized before removing the guard
D) Loosen the guard bolts while the machine is still running
Answer: C
Rationale: Rotating equipment must be made safe before guards are removed. Isolation prevents
unexpected movement and exposure to moving parts .
2. A pipe must be cut and threaded for installation. Which sequence is most appropriate?
A) Thread the pipe, then cut it to length
B) Measure, cut, deburr, and then thread the pipe
C) Heat the pipe before measuring
D) Thread both ends before cutting
Answer: B
Rationale: Accurate measurement and cutting should precede threading. Deburring removes sharp
edges and helps produce a clean thread .
,3. A drill press begins producing a hole that is larger than the selected drill bit. What is the most likely
concern?
A) The workpiece is too clean
B) The drill press table is too low
C) The workpiece may not be secure or the drill may be damaged
D) The cutting speed is always too slow
Answer: C
Rationale: An improperly secured workpiece or damaged/bent tooling can cause the drill to wander and
produce an oversized hole .
4. Before operating a portable grinder, which condition requires immediate correction?
A) The workpiece is painted
B) The operator is wearing safety glasses
C) The grinding wheel has a visible crack
D) The grinder has a grounded plug
Answer: C
Rationale: A cracked grinding wheel can fail catastrophically during operation and must not be used .
,5. A mechanic tells a helper to hold a component while it is being drilled. The component begins shifting.
What is the safest response?
A) Hold it harder with one hand
B) Continue drilling at reduced speed
C) Stop and secure the component properly with a clamp or vise
D) Ask the mechanic to drill faster
Answer: C
Rationale: The workpiece should be secured with an appropriate clamp, vise, or fixture rather than held
by hand .
6. A wrench slips while loosening a fastener. Which action best reduces the likelihood of another slip?
A) Use a longer unrelated tool
B) Strike the wrench continuously
C) Use the correctly sized wrench fully engaged on the fastener
D) Hold the wrench at an angle
Answer: C
Rationale: Proper fit and full engagement provide better control and reduce slipping .
7. A helper is assisting with a suspended machine component. The load begins swinging. What should
the helper do?
A) Push the load while standing beneath it
, B) Grab the load with both hands
C) Keep clear of the suspended load and control the operation as directed
D) Stand underneath it to stabilize it
Answer: C
Rationale: Personnel should remain outside the danger zone of suspended loads. Loads should be
controlled using proper rigging and procedures .
8. A hoist is rated for 2,000 pounds. A component weighs approximately 2,100 pounds. What should the
helper do?
A) Lift it because the difference is small
B) Lift it slowly
C) Use two people to pull on it
D) Do not lift it with that hoist
Answer: D
Rationale: The rated capacity must not be exceeded. Appropriate lifting equipment with sufficient
capacity is required .
9. Which tool is generally most appropriate for gripping and turning a hexagonal fastener?
A) Pipe wrench
B) Box or socket wrench of the correct size
C) Slipjoint pliers
D) Adjustable wrench
