NYC Custodian Engineer Exam Questions With Correct
Answers (Verified Answers) Plus Rationales | 2026
1. Which hand tool is designed primarily to turn a hexagonal nut or bolt head?
Adjustable wrench
• Cold chisel
• Slip-joint pliers
• Ball-peen
Rationale:hammer
An adjustable wrench is designed to grip and turn nuts and bolts of different sizes.
2. Which tool is most appropriate for checking whether an electrical circuit is energized?
• Tape measure
Non-contact voltage tester
• Pipe wrench
• Putty knife A properly rated voltage tester is used to determine the presence of electrical voltage.
Rationale:
3. Before using a power tool with a damaged electrical cord, what should the custodian engineer
do?
• Wrap the cord with paper
• Use it only at low speed
Remove it from service and have it repaired or replaced
• Submerge
Rationale: the plug incords
Damaged watercan expose workers to shock and fire hazards and should be removed from service.
4. What is the primary purpose of safety glasses when operating a drill?
• Improve hearing
Protect the eyes from flying particles
• Prevent hand fatigue
• Increase drill speed
Rationale: Safety glasses protect the eyes from chips, dust, and other flying particles.
5. A wrench that is slipping on a fastener most directly increases the risk of what?
Stripped fastener and hand injury
• Lower water pressure
• Boiler foaming
• Poor paint adhesion
Rationale: A slipping wrench can damage the fastener and cause the worker's hand to strike nearby surfaces.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 1
, 6. Which tool is normally used to measure electrical resistance?
Ohmmeter
• Thermometer
• Manometer
• Hygrometer
Rationale: An ohmmeter measures electrical resistance in ohms.
Official NYC DCAS Exam No. 6042 Notice of Examination (documentary reference).
7. What should be done before changing a blade on a power saw?
• Increase the motor speed
Disconnect or isolate the power source according to the manufacturer's procedure
• Add more lubricant to the floor
• Open a fire The
sprinkler
Rationale: powervalve
source must be isolated before servicing cutting equipment.
8. Which tool is best suited for tightening a pipe fitting without damaging a smooth cylindrical
pipe?
Pipe wrench
• Wood rasp
• Phillips screwdriver
• Tin snips A pipe wrench is designed to grip and turn threaded pipe and fittings.
Rationale:
9. Why should a tool be selected that matches the fastener head?
To reduce the chance of slipping and damaging the fastener
• To make the tool heavier
• To increase electrical resistance
• To make paint dry faster
Rationale: A properly fitting tool transfers force safely and reduces slipping.
10. What is the safest general practice when carrying a sharp hand tool?
• Carry it loosely in a pocket
• Point the sharp end toward other people
Use a suitable holder or carry it with the sharp end controlled
• Throw it to another worker
Rationale: Sharp tools should be carried in a controlled manner, preferably with a protective holder.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 2
, 11. What does a torque wrench allow a technician to control?
Fastener tightening torque
• Water temperature
• Room humidity
• Paint color A torque wrench is used to apply a specified tightening torque.
Rationale:
12. Why should guards on power tools remain in place?
They reduce exposure to moving or cutting parts
• They make the tool quieter only
• They increase fuel pressure
• They replace PPE are engineered to reduce contact with hazardous moving parts.
Rationale: Guards
13. Which item provides hearing protection?
Earplugs
• Safety glasses
• Leather apron
• Steel ruler Earplugs reduce exposure to hazardous noise.
Rationale:
14. What is the main purpose of a lockout/tagout procedure?
Prevent unexpected energization or startup during servicing
• Increase boiler pressure
• Improve paint gloss
• Speed up cleaning
Rationale: Lockout/tagout controls hazardous energy while equipment is being serviced.
15. A ladder should generally be inspected for what before use?
Defects, damage, contamination, and secure components
• Paint color only
• Boiler water chemistry
• Room temperature only
Rationale: A pre-use inspection identifies conditions that could cause a fall.
16. What is the safest way to use a ladder on an uneven floor?
• Place cardboard under one foot
Use an approved leveling method or relocate the ladder to a level surface
• Stand on the top cap
• Lean it against a moving
Rationale: Ladders shoulddoor
be stable and level; improvised supports can cause falls.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 3
, 17. Why should compressed air not be directed at a person's clothing or skin?
It can cause serious injury and drive particles into the body
• It improves circulation too much
• It lowers room humidity
• ItRationale:
makes theCompressed
compressorair
more
can efficient
injure skin, eyes, and hearing and can propel debris.
18. What is the purpose of a flashlight during a power outage inspection?
Provide illumination while avoiding unsafe improvisation with energized equipment
• Increase generator voltage
• Dry wet floors
• Test boiler pressure
Rationale: Adequate portable lighting helps personnel inspect safely during loss of normal lighting.
19. When using a chemical product, where should the worker look for required handling information?
The product label and Safety Data Sheet
• A random internet comment
• The paint color chart
• The payroll The
formlabel and SDS provide hazard, handling, PPE, storage, and first-aid information.
Rationale:
20. Why should hand tools be kept clean and dry when appropriate?
To improve grip, function, and condition
• To increase their electrical voltage
• To make them heavier
• To reduce the need for inspections
Rationale: Clean, serviceable tools are safer and function more reliably.
21. Which practice best reduces trip hazards in a mechanical room?
Route and secure hoses, cords, and materials away from walkways
• Leave cords across doors
• Store tools on stairs
• Place oily rags in thewalkways
center ofclear
the floor
Rationale: Keeping reduces slips, trips, and falls.
22. What should a worker do if a tool becomes unusually hot, vibrates excessively, or makes an
abnormal noise?
Stop using it and inspect/report the problem
• Ignore it until it fails completely
• Increase speed
• Cover it withAbnormal
a rag while running
Rationale: operation can indicate a defect requiring isolation and inspection.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 4
Answers (Verified Answers) Plus Rationales | 2026
1. Which hand tool is designed primarily to turn a hexagonal nut or bolt head?
Adjustable wrench
• Cold chisel
• Slip-joint pliers
• Ball-peen
Rationale:hammer
An adjustable wrench is designed to grip and turn nuts and bolts of different sizes.
2. Which tool is most appropriate for checking whether an electrical circuit is energized?
• Tape measure
Non-contact voltage tester
• Pipe wrench
• Putty knife A properly rated voltage tester is used to determine the presence of electrical voltage.
Rationale:
3. Before using a power tool with a damaged electrical cord, what should the custodian engineer
do?
• Wrap the cord with paper
• Use it only at low speed
Remove it from service and have it repaired or replaced
• Submerge
Rationale: the plug incords
Damaged watercan expose workers to shock and fire hazards and should be removed from service.
4. What is the primary purpose of safety glasses when operating a drill?
• Improve hearing
Protect the eyes from flying particles
• Prevent hand fatigue
• Increase drill speed
Rationale: Safety glasses protect the eyes from chips, dust, and other flying particles.
5. A wrench that is slipping on a fastener most directly increases the risk of what?
Stripped fastener and hand injury
• Lower water pressure
• Boiler foaming
• Poor paint adhesion
Rationale: A slipping wrench can damage the fastener and cause the worker's hand to strike nearby surfaces.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 1
, 6. Which tool is normally used to measure electrical resistance?
Ohmmeter
• Thermometer
• Manometer
• Hygrometer
Rationale: An ohmmeter measures electrical resistance in ohms.
Official NYC DCAS Exam No. 6042 Notice of Examination (documentary reference).
7. What should be done before changing a blade on a power saw?
• Increase the motor speed
Disconnect or isolate the power source according to the manufacturer's procedure
• Add more lubricant to the floor
• Open a fire The
sprinkler
Rationale: powervalve
source must be isolated before servicing cutting equipment.
8. Which tool is best suited for tightening a pipe fitting without damaging a smooth cylindrical
pipe?
Pipe wrench
• Wood rasp
• Phillips screwdriver
• Tin snips A pipe wrench is designed to grip and turn threaded pipe and fittings.
Rationale:
9. Why should a tool be selected that matches the fastener head?
To reduce the chance of slipping and damaging the fastener
• To make the tool heavier
• To increase electrical resistance
• To make paint dry faster
Rationale: A properly fitting tool transfers force safely and reduces slipping.
10. What is the safest general practice when carrying a sharp hand tool?
• Carry it loosely in a pocket
• Point the sharp end toward other people
Use a suitable holder or carry it with the sharp end controlled
• Throw it to another worker
Rationale: Sharp tools should be carried in a controlled manner, preferably with a protective holder.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 2
, 11. What does a torque wrench allow a technician to control?
Fastener tightening torque
• Water temperature
• Room humidity
• Paint color A torque wrench is used to apply a specified tightening torque.
Rationale:
12. Why should guards on power tools remain in place?
They reduce exposure to moving or cutting parts
• They make the tool quieter only
• They increase fuel pressure
• They replace PPE are engineered to reduce contact with hazardous moving parts.
Rationale: Guards
13. Which item provides hearing protection?
Earplugs
• Safety glasses
• Leather apron
• Steel ruler Earplugs reduce exposure to hazardous noise.
Rationale:
14. What is the main purpose of a lockout/tagout procedure?
Prevent unexpected energization or startup during servicing
• Increase boiler pressure
• Improve paint gloss
• Speed up cleaning
Rationale: Lockout/tagout controls hazardous energy while equipment is being serviced.
15. A ladder should generally be inspected for what before use?
Defects, damage, contamination, and secure components
• Paint color only
• Boiler water chemistry
• Room temperature only
Rationale: A pre-use inspection identifies conditions that could cause a fall.
16. What is the safest way to use a ladder on an uneven floor?
• Place cardboard under one foot
Use an approved leveling method or relocate the ladder to a level surface
• Stand on the top cap
• Lean it against a moving
Rationale: Ladders shoulddoor
be stable and level; improvised supports can cause falls.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 3
, 17. Why should compressed air not be directed at a person's clothing or skin?
It can cause serious injury and drive particles into the body
• It improves circulation too much
• It lowers room humidity
• ItRationale:
makes theCompressed
compressorair
more
can efficient
injure skin, eyes, and hearing and can propel debris.
18. What is the purpose of a flashlight during a power outage inspection?
Provide illumination while avoiding unsafe improvisation with energized equipment
• Increase generator voltage
• Dry wet floors
• Test boiler pressure
Rationale: Adequate portable lighting helps personnel inspect safely during loss of normal lighting.
19. When using a chemical product, where should the worker look for required handling information?
The product label and Safety Data Sheet
• A random internet comment
• The paint color chart
• The payroll The
formlabel and SDS provide hazard, handling, PPE, storage, and first-aid information.
Rationale:
20. Why should hand tools be kept clean and dry when appropriate?
To improve grip, function, and condition
• To increase their electrical voltage
• To make them heavier
• To reduce the need for inspections
Rationale: Clean, serviceable tools are safer and function more reliably.
21. Which practice best reduces trip hazards in a mechanical room?
Route and secure hoses, cords, and materials away from walkways
• Leave cords across doors
• Store tools on stairs
• Place oily rags in thewalkways
center ofclear
the floor
Rationale: Keeping reduces slips, trips, and falls.
22. What should a worker do if a tool becomes unusually hot, vibrates excessively, or makes an
abnormal noise?
Stop using it and inspect/report the problem
• Ignore it until it fails completely
• Increase speed
• Cover it withAbnormal
a rag while running
Rationale: operation can indicate a defect requiring isolation and inspection.
NYC Custodian Engineer (BOE) — 250-question practice workbook — 2026 Page 4
