NYC CUSTODIAN ENGINEER COMPLETE EXAM
QUESTIONS AND VERIFIED ANSWERS | 2026–
2027 LATEST UPDATE | GUARANTEED PASS |
DETAILED RATIONALES | FULL STUDY GUIDE |
EXAM PREP | PRACTICE TEST | CERTIFICATION
PREPARATION
Section One — Questions 1–100
1. Which tool is most appropriate for tightening or loosening a hexagonal nut
when the correct size is known?
A) Pipe wrench
B) Slip-joint pliers
C) Adjustable strap wrench
D) Combination wrench
Correct Answer: D) Combination wrench
Rationale: A combination wrench has a fixed-size open end and a box end designed to fit
hexagonal fasteners. Using the correctly sized wrench reduces the likelihood of rounding the
fastener or slipping. Pipe wrenches are intended primarily for gripping round pipe and can
damage hexagonal fasteners. Pliers are less precise.
2. Before using a portable electric drill on a job, what should the engineer do
first?
A) Inspect the cord, plug, housing, and controls for damage
B) Increase the drill speed to maximum
C) Remove the equipment grounding connection
D) Lubricate the electrical cord
Correct Answer: A) Inspect the cord, plug, housing, and controls for damage
Rationale: A pre-use inspection identifies damaged insulation, defective plugs, cracked housings,
or malfunctioning controls before energized equipment is handled. Such defects can create
,shock, fire, or mechanical hazards. Increasing speed does not address safety, grounding must
not be defeated, and electrical cords should never be treated as mechanical components
requiring routine lubrication.
3. A wrench slips repeatedly from a fastener because the wrench is slightly too
large. What is the best action?
A) Strike the wrench harder
B) Select the properly sized wrench
C) Add oil to the fastener
D) Use a pipe wrench instead
Correct Answer: B) Select the properly sized wrench
Rationale: The correct wrench size provides proper contact with the fastener flats and reduces
slipping. Using an oversized wrench can round the fastener and injure the worker if the tool
suddenly releases. Striking a wrench is not an appropriate substitute for proper sizing, and a
pipe wrench is not designed for this application.
4. What is the primary purpose of a voltage tester when servicing an electrical
circuit?
A) Determine wire insulation thickness
B) Measure water pressure
C) Determine whether electrical potential is present
D) Identify the conductor's material
Correct Answer: C) Determine whether electrical potential is present
Rationale: A properly rated voltage tester is used to determine whether electrical potential exists
between specified points. This is especially important before beginning electrical work because a
circuit that appears inactive may still be energized. The tester does not determine insulation
thickness, water pressure, or conductor composition.
5. When operating a gasoline-powered piece of grounds equipment indoors,
which concern is most important?
A) Carbon monoxide accumulation
,B) Excessive paint drying
C) Low water hardness
D) Increased pipe pressure
Correct Answer: A) Carbon monoxide accumulation
Rationale: Internal-combustion engines can produce carbon monoxide, an odorless and
potentially fatal gas. Operating gasoline-powered equipment in an enclosed or poorly ventilated
area can allow dangerous concentrations to accumulate. Proper ventilation, outdoor operation
when appropriate, and adherence to equipment instructions are essential. The other choices do
not represent the primary hazard.
6. What is the principal purpose of using the correct screwdriver size for a screw
head?
A) Increase electrical voltage
B) Prevent damage to the fastener and tool
C) Increase motor speed
D) Reduce water temperature
Correct Answer: B) Prevent damage to the fastener and tool
Rationale: A properly sized screwdriver engages the screw head correctly and allows controlled
torque. An improperly sized driver can damage the screw slot, damage the tool, or cause the
driver to slip and injure the operator. Tool selection is therefore an important part of safe and
effective maintenance work.
7. Which practice is most appropriate when using a power saw?
A) Remove the guard for better visibility
B) Hold the material with the hand directly beside the blade
C) Follow the manufacturer's guarding and operating requirements
D) Increase blade speed beyond the rated specification
Correct Answer: C) Follow the manufacturer's guarding and operating requirements
Rationale: Power saws should be operated according to manufacturer instructions, including
required guards, blade selection, work positioning, and operating limits. Removing guards or
, placing hands near moving blades increases injury risk. Exceeding rated operating
specifications can also create mechanical failure. Safe operation depends on maintaining
engineered protections.
8. Which cleaning product is generally intended to remove accumulated floor
finish before applying a new finish?
A) Neutral cleaner
B) Floor stripper
C) Glass cleaner
D) Disinfectant only
Correct Answer: B) Floor stripper
Rationale: Floor stripper is formulated to loosen and remove existing floor finish, allowing the
surface to be properly prepared before refinishing. Neutral cleaners are generally intended for
routine cleaning of finished surfaces. Glass cleaners target glass and similar surfaces, while
disinfectants serve microbial-control purposes rather than primarily removing old floor finish.
9. Why should cleaning chemicals be stored in properly labeled containers?
A) To increase their concentration
B) To make them evaporate faster
C) To eliminate the need for ventilation
D) To identify contents and communicate hazards
Correct Answer: D) To identify contents and communicate hazards
Rationale: Proper labeling allows workers to identify chemical contents, hazards, handling
requirements, and appropriate precautions. Unlabeled containers can lead to accidental misuse,
incompatible mixing, or improper emergency response. Labeling is therefore an important
component of chemical safety and supports informed handling, storage, and response
procedures.
10. What is the safest general practice when diluting a concentrated cleaning
chemical?
A) Follow the product label and required dilution instructions
B) Mix it by guessing the amount of water
QUESTIONS AND VERIFIED ANSWERS | 2026–
2027 LATEST UPDATE | GUARANTEED PASS |
DETAILED RATIONALES | FULL STUDY GUIDE |
EXAM PREP | PRACTICE TEST | CERTIFICATION
PREPARATION
Section One — Questions 1–100
1. Which tool is most appropriate for tightening or loosening a hexagonal nut
when the correct size is known?
A) Pipe wrench
B) Slip-joint pliers
C) Adjustable strap wrench
D) Combination wrench
Correct Answer: D) Combination wrench
Rationale: A combination wrench has a fixed-size open end and a box end designed to fit
hexagonal fasteners. Using the correctly sized wrench reduces the likelihood of rounding the
fastener or slipping. Pipe wrenches are intended primarily for gripping round pipe and can
damage hexagonal fasteners. Pliers are less precise.
2. Before using a portable electric drill on a job, what should the engineer do
first?
A) Inspect the cord, plug, housing, and controls for damage
B) Increase the drill speed to maximum
C) Remove the equipment grounding connection
D) Lubricate the electrical cord
Correct Answer: A) Inspect the cord, plug, housing, and controls for damage
Rationale: A pre-use inspection identifies damaged insulation, defective plugs, cracked housings,
or malfunctioning controls before energized equipment is handled. Such defects can create
,shock, fire, or mechanical hazards. Increasing speed does not address safety, grounding must
not be defeated, and electrical cords should never be treated as mechanical components
requiring routine lubrication.
3. A wrench slips repeatedly from a fastener because the wrench is slightly too
large. What is the best action?
A) Strike the wrench harder
B) Select the properly sized wrench
C) Add oil to the fastener
D) Use a pipe wrench instead
Correct Answer: B) Select the properly sized wrench
Rationale: The correct wrench size provides proper contact with the fastener flats and reduces
slipping. Using an oversized wrench can round the fastener and injure the worker if the tool
suddenly releases. Striking a wrench is not an appropriate substitute for proper sizing, and a
pipe wrench is not designed for this application.
4. What is the primary purpose of a voltage tester when servicing an electrical
circuit?
A) Determine wire insulation thickness
B) Measure water pressure
C) Determine whether electrical potential is present
D) Identify the conductor's material
Correct Answer: C) Determine whether electrical potential is present
Rationale: A properly rated voltage tester is used to determine whether electrical potential exists
between specified points. This is especially important before beginning electrical work because a
circuit that appears inactive may still be energized. The tester does not determine insulation
thickness, water pressure, or conductor composition.
5. When operating a gasoline-powered piece of grounds equipment indoors,
which concern is most important?
A) Carbon monoxide accumulation
,B) Excessive paint drying
C) Low water hardness
D) Increased pipe pressure
Correct Answer: A) Carbon monoxide accumulation
Rationale: Internal-combustion engines can produce carbon monoxide, an odorless and
potentially fatal gas. Operating gasoline-powered equipment in an enclosed or poorly ventilated
area can allow dangerous concentrations to accumulate. Proper ventilation, outdoor operation
when appropriate, and adherence to equipment instructions are essential. The other choices do
not represent the primary hazard.
6. What is the principal purpose of using the correct screwdriver size for a screw
head?
A) Increase electrical voltage
B) Prevent damage to the fastener and tool
C) Increase motor speed
D) Reduce water temperature
Correct Answer: B) Prevent damage to the fastener and tool
Rationale: A properly sized screwdriver engages the screw head correctly and allows controlled
torque. An improperly sized driver can damage the screw slot, damage the tool, or cause the
driver to slip and injure the operator. Tool selection is therefore an important part of safe and
effective maintenance work.
7. Which practice is most appropriate when using a power saw?
A) Remove the guard for better visibility
B) Hold the material with the hand directly beside the blade
C) Follow the manufacturer's guarding and operating requirements
D) Increase blade speed beyond the rated specification
Correct Answer: C) Follow the manufacturer's guarding and operating requirements
Rationale: Power saws should be operated according to manufacturer instructions, including
required guards, blade selection, work positioning, and operating limits. Removing guards or
, placing hands near moving blades increases injury risk. Exceeding rated operating
specifications can also create mechanical failure. Safe operation depends on maintaining
engineered protections.
8. Which cleaning product is generally intended to remove accumulated floor
finish before applying a new finish?
A) Neutral cleaner
B) Floor stripper
C) Glass cleaner
D) Disinfectant only
Correct Answer: B) Floor stripper
Rationale: Floor stripper is formulated to loosen and remove existing floor finish, allowing the
surface to be properly prepared before refinishing. Neutral cleaners are generally intended for
routine cleaning of finished surfaces. Glass cleaners target glass and similar surfaces, while
disinfectants serve microbial-control purposes rather than primarily removing old floor finish.
9. Why should cleaning chemicals be stored in properly labeled containers?
A) To increase their concentration
B) To make them evaporate faster
C) To eliminate the need for ventilation
D) To identify contents and communicate hazards
Correct Answer: D) To identify contents and communicate hazards
Rationale: Proper labeling allows workers to identify chemical contents, hazards, handling
requirements, and appropriate precautions. Unlabeled containers can lead to accidental misuse,
incompatible mixing, or improper emergency response. Labeling is therefore an important
component of chemical safety and supports informed handling, storage, and response
procedures.
10. What is the safest general practice when diluting a concentrated cleaning
chemical?
A) Follow the product label and required dilution instructions
B) Mix it by guessing the amount of water
