NYC STATIONARY ENGINEER EXAMINATION NEWEST EVALUATED EXAM
PRACTICE 100 QUESTIONS 2026-2027|ORIGINAL QUESTIONS & ANSWERS
|DETAILED RATIONALES |HINTED COMPLETE EXAM PREP GRADED
A+*INSTANT DOWNLOAD PDF*
1. A centrifugal pump is operating at constant speed, but its discharge
pressure has decreased significantly while the suction pressure remains
normal. Which condition is MOST likely?
A. Excessive motor insulation resistance
B. Impeller wear or damage
C. Increased electrical frequency
D. Oversized coupling
Answer: B. Impeller wear or damage
An eroded, damaged, or excessively worn impeller reduces the pump’s ability
to develop the required head and discharge pressure.
2. A steam boiler’s water level is falling even though the feedwater pump is
running. Which condition should the engineer investigate FIRST?
A. Excessive burner draft
B. Feedwater flow restriction or pump failure
C. High condensate temperature
D. Excessive lubrication
Answer: B. Feedwater flow restriction or pump failure
Loss or restriction of feedwater can cause the boiler water level to fall
dangerously and must be investigated immediately.
3. What is the primary purpose of a low-water cutoff on a steam boiler?
A. To regulate fuel pressure
B. To prevent excessive steam pressure
C. To shut down the burner when boiler water becomes dangerously low
D. To increase combustion efficiency
Answer: C. To shut down the burner when boiler water becomes dangerously
low
,The low-water cutoff protects the boiler from overheating and possible
catastrophic damage when the water level falls below a safe limit.
4. A boiler safety valve begins lifting repeatedly even though the operating
pressure appears to be below the normal setting. What should be
suspected?
A. Incorrect pressure indication or faulty safety valve
B. Low combustion temperature
C. Excessive feedwater treatment
D. Low condensate temperature
Answer: A. Incorrect pressure indication or faulty safety valve
Repeated lifting below the expected set pressure indicates that the pressure
indication or safety valve operation should be investigated.
5. Which instrument is most appropriate for measuring differential
pressure across a filter?
A. Thermocouple
B. Manometer or differential-pressure gauge
C. Megohmmeter
D. Tachometer
Answer: B. Manometer or differential-pressure gauge
A differential-pressure instrument compares pressure upstream and
downstream of the filter and can indicate filter loading.
6. A motor draws excessive current immediately after starting and remains
above its normal operating current. Which condition is MOST likely?
A. Mechanical overload
B. Excessive bearing clearance only
C. Low atmospheric humidity
D. High insulation resistance
Answer: A. Mechanical overload
An overloaded motor requires increased torque and therefore draws excessive
current.
, 7. Under Ohm’s law, if resistance remains constant and voltage is doubled,
current will:
A. Be reduced by half
B. Remain unchanged
C. Double
D. Increase four times
Answer: C. Double
Ohm’s law states that I = V/R. With resistance constant, doubling voltage
doubles current.
8. A 240-volt circuit has a resistance of 12 ohms. What current should
theoretically flow?
A. 10 A
B. 20 A
C. 28.8 A
D. 2 A
Answer: B. 20 A
Using I = V/R, I = 240/12 = 20 amperes.
9. What is the primary purpose of a circuit breaker?
A. Increase circuit voltage
B. Provide overcurrent protection and interrupt a fault
C. Increase motor speed
D. Reduce conductor resistance
Answer: B. Provide overcurrent protection and interrupt a fault
A circuit breaker automatically interrupts excessive current to protect
conductors and equipment.
10. Before working on energized electrical equipment, the MOST
appropriate general safety principle is to:
A. Increase the equipment load
B. De-energize, isolate, and verify absence of hazardous energy when possible
, C. Remove only the equipment cover
D. Wear ordinary work gloves
Answer: B. De-energize, isolate, and verify absence of hazardous energy
when possible
Electrical energy should be isolated and absence of voltage verified before
work whenever the procedure permits.
11. A three-phase motor is rotating in the wrong direction after
maintenance. What is the most direct correction?
A. Increase the voltage
B. Reverse any two phase connections
C. Replace all three conductors
D. Increase the fuse rating
Answer: B. Reverse any two phase connections
Interchanging any two phases reverses the rotating magnetic field and
therefore reverses motor rotation.
12. A pump motor runs normally but the pump produces little or no flow.
Which condition should be checked FIRST?
A. Pump rotation and suction condition
B. Motor paint condition
C. Room lighting
D. Bearing grease color only
Answer: A. Pump rotation and suction condition
Incorrect rotation, loss of prime, blocked suction, or inadequate suction
conditions can prevent proper pumping.
13. What is cavitation in a centrifugal pump?
A. Electrical arcing inside the motor
B. Formation and collapse of vapor bubbles caused by insufficient suction
pressure
C. Excessive lubrication of bearings
D. Expansion of pump casing due to freezing
PRACTICE 100 QUESTIONS 2026-2027|ORIGINAL QUESTIONS & ANSWERS
|DETAILED RATIONALES |HINTED COMPLETE EXAM PREP GRADED
A+*INSTANT DOWNLOAD PDF*
1. A centrifugal pump is operating at constant speed, but its discharge
pressure has decreased significantly while the suction pressure remains
normal. Which condition is MOST likely?
A. Excessive motor insulation resistance
B. Impeller wear or damage
C. Increased electrical frequency
D. Oversized coupling
Answer: B. Impeller wear or damage
An eroded, damaged, or excessively worn impeller reduces the pump’s ability
to develop the required head and discharge pressure.
2. A steam boiler’s water level is falling even though the feedwater pump is
running. Which condition should the engineer investigate FIRST?
A. Excessive burner draft
B. Feedwater flow restriction or pump failure
C. High condensate temperature
D. Excessive lubrication
Answer: B. Feedwater flow restriction or pump failure
Loss or restriction of feedwater can cause the boiler water level to fall
dangerously and must be investigated immediately.
3. What is the primary purpose of a low-water cutoff on a steam boiler?
A. To regulate fuel pressure
B. To prevent excessive steam pressure
C. To shut down the burner when boiler water becomes dangerously low
D. To increase combustion efficiency
Answer: C. To shut down the burner when boiler water becomes dangerously
low
,The low-water cutoff protects the boiler from overheating and possible
catastrophic damage when the water level falls below a safe limit.
4. A boiler safety valve begins lifting repeatedly even though the operating
pressure appears to be below the normal setting. What should be
suspected?
A. Incorrect pressure indication or faulty safety valve
B. Low combustion temperature
C. Excessive feedwater treatment
D. Low condensate temperature
Answer: A. Incorrect pressure indication or faulty safety valve
Repeated lifting below the expected set pressure indicates that the pressure
indication or safety valve operation should be investigated.
5. Which instrument is most appropriate for measuring differential
pressure across a filter?
A. Thermocouple
B. Manometer or differential-pressure gauge
C. Megohmmeter
D. Tachometer
Answer: B. Manometer or differential-pressure gauge
A differential-pressure instrument compares pressure upstream and
downstream of the filter and can indicate filter loading.
6. A motor draws excessive current immediately after starting and remains
above its normal operating current. Which condition is MOST likely?
A. Mechanical overload
B. Excessive bearing clearance only
C. Low atmospheric humidity
D. High insulation resistance
Answer: A. Mechanical overload
An overloaded motor requires increased torque and therefore draws excessive
current.
, 7. Under Ohm’s law, if resistance remains constant and voltage is doubled,
current will:
A. Be reduced by half
B. Remain unchanged
C. Double
D. Increase four times
Answer: C. Double
Ohm’s law states that I = V/R. With resistance constant, doubling voltage
doubles current.
8. A 240-volt circuit has a resistance of 12 ohms. What current should
theoretically flow?
A. 10 A
B. 20 A
C. 28.8 A
D. 2 A
Answer: B. 20 A
Using I = V/R, I = 240/12 = 20 amperes.
9. What is the primary purpose of a circuit breaker?
A. Increase circuit voltage
B. Provide overcurrent protection and interrupt a fault
C. Increase motor speed
D. Reduce conductor resistance
Answer: B. Provide overcurrent protection and interrupt a fault
A circuit breaker automatically interrupts excessive current to protect
conductors and equipment.
10. Before working on energized electrical equipment, the MOST
appropriate general safety principle is to:
A. Increase the equipment load
B. De-energize, isolate, and verify absence of hazardous energy when possible
, C. Remove only the equipment cover
D. Wear ordinary work gloves
Answer: B. De-energize, isolate, and verify absence of hazardous energy
when possible
Electrical energy should be isolated and absence of voltage verified before
work whenever the procedure permits.
11. A three-phase motor is rotating in the wrong direction after
maintenance. What is the most direct correction?
A. Increase the voltage
B. Reverse any two phase connections
C. Replace all three conductors
D. Increase the fuse rating
Answer: B. Reverse any two phase connections
Interchanging any two phases reverses the rotating magnetic field and
therefore reverses motor rotation.
12. A pump motor runs normally but the pump produces little or no flow.
Which condition should be checked FIRST?
A. Pump rotation and suction condition
B. Motor paint condition
C. Room lighting
D. Bearing grease color only
Answer: A. Pump rotation and suction condition
Incorrect rotation, loss of prime, blocked suction, or inadequate suction
conditions can prevent proper pumping.
13. What is cavitation in a centrifugal pump?
A. Electrical arcing inside the motor
B. Formation and collapse of vapor bubbles caused by insufficient suction
pressure
C. Excessive lubrication of bearings
D. Expansion of pump casing due to freezing
