1|Page
Q-01 FDNY EXAM LATEST 2025/2026 ACTUAL EXAM WITH
COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (100%
VERIFIED ANSWERS) |ALREADY GRADED A+| ||PROFESSOR
VERIFIED|| ||BRANDNEW!!!||
In order to vary the specific capacity of an absorption refrigerating
plant, an operating engineer should regulate the
A) Flow of steam to the generator, and adjust the expansion
valve.
B) Relief valves on the generator, and the speed of the NH2
pump.
C) Speed of the absorber pump.
D) Flow of water to the condenser. - ANSWER-A) Flow of steam
to the generator, and adjust the expansion valve.
The refrigerant least miscible in oil is
A) CO2
B) R-12
C) R-40
D) R-141 - ANSWER-A) CO2
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The first sign that the drum of ammonia refrigerant is almost
empty is
A) The appearance of frost on the lower end of the drum
B) The appearance of fog in the vicinity of the drum
C) A hissing or whistling noise in the drum
D) A gurgling noise - ANSWER-C) A hissing or whistling noise in
the drum
What is the total force exerted on a piston 3" in diameter if
pressure in the cylinder is 100 psig? - ANSWER-πR2 x pressure
1.14 x 1.52 x 100
3.14 x 2.25 x 100
7.065 x 100
706.5 psi
Breathing apparatus
1) A machine room with 1-1,000 lbs. of refrigerant needs how
many masks?
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2) A machine room with 1,001-2,000 lbs. of refrigerant needs how
many masks? - ANSWER-1) 1 - 1,000 lbs. = 1 mask
2) 1,001 - 2,000 lbs. = 2 masks
Safety valve huddling chamber
1) How is the design important to the function of the huddling
chamber?
2) What is a huddling chamber?
3) Where is the exact location of it on the machine? - ANSWER-1)
Design- The huddling chamber has a greater diameter that the
pipe thereby having a greater total force to open the relief valve
2) Pressure relief valve
3) On the suction elbow
Depletion of the ozone results in three types of skin cancer. Which
of the following are the most common non-malignant type of skin
cancer?
A) Basal, squamous
B) Malignant melanoma
C) Cataracts
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D) Leishmaniosis - ANSWER-A) Basal, squamous
The suction temperature of an ammonia system reads 50° F. This
temperature is equivalent to _____ psi. - ANSWER-75 psi
During the re-expansion of the compressor cycle
A) The suction valve is open
B) The suction valve is closed
C) The discharge valve is open
D) None of the above - ANSWER-B) The suction valve is closed
Where is the king valve located? Mention some details about it. -
ANSWER-The king valve is located next to the condenser or
receiver outlet; it can be located on the receiver; it can be used as
the liquid line service valve.
How is an evaporator defrosted? - ANSWER-Hot gas from the
discharge line is sent to the evaporator after the metering device.
Q-01 FDNY EXAM LATEST 2025/2026 ACTUAL EXAM WITH
COMPLETE QUESTIONS AND CORRECT DETAILED ANSWERS (100%
VERIFIED ANSWERS) |ALREADY GRADED A+| ||PROFESSOR
VERIFIED|| ||BRANDNEW!!!||
In order to vary the specific capacity of an absorption refrigerating
plant, an operating engineer should regulate the
A) Flow of steam to the generator, and adjust the expansion
valve.
B) Relief valves on the generator, and the speed of the NH2
pump.
C) Speed of the absorber pump.
D) Flow of water to the condenser. - ANSWER-A) Flow of steam
to the generator, and adjust the expansion valve.
The refrigerant least miscible in oil is
A) CO2
B) R-12
C) R-40
D) R-141 - ANSWER-A) CO2
,2|Page
The first sign that the drum of ammonia refrigerant is almost
empty is
A) The appearance of frost on the lower end of the drum
B) The appearance of fog in the vicinity of the drum
C) A hissing or whistling noise in the drum
D) A gurgling noise - ANSWER-C) A hissing or whistling noise in
the drum
What is the total force exerted on a piston 3" in diameter if
pressure in the cylinder is 100 psig? - ANSWER-πR2 x pressure
1.14 x 1.52 x 100
3.14 x 2.25 x 100
7.065 x 100
706.5 psi
Breathing apparatus
1) A machine room with 1-1,000 lbs. of refrigerant needs how
many masks?
,3|Page
2) A machine room with 1,001-2,000 lbs. of refrigerant needs how
many masks? - ANSWER-1) 1 - 1,000 lbs. = 1 mask
2) 1,001 - 2,000 lbs. = 2 masks
Safety valve huddling chamber
1) How is the design important to the function of the huddling
chamber?
2) What is a huddling chamber?
3) Where is the exact location of it on the machine? - ANSWER-1)
Design- The huddling chamber has a greater diameter that the
pipe thereby having a greater total force to open the relief valve
2) Pressure relief valve
3) On the suction elbow
Depletion of the ozone results in three types of skin cancer. Which
of the following are the most common non-malignant type of skin
cancer?
A) Basal, squamous
B) Malignant melanoma
C) Cataracts
, 4|Page
D) Leishmaniosis - ANSWER-A) Basal, squamous
The suction temperature of an ammonia system reads 50° F. This
temperature is equivalent to _____ psi. - ANSWER-75 psi
During the re-expansion of the compressor cycle
A) The suction valve is open
B) The suction valve is closed
C) The discharge valve is open
D) None of the above - ANSWER-B) The suction valve is closed
Where is the king valve located? Mention some details about it. -
ANSWER-The king valve is located next to the condenser or
receiver outlet; it can be located on the receiver; it can be used as
the liquid line service valve.
How is an evaporator defrosted? - ANSWER-Hot gas from the
discharge line is sent to the evaporator after the metering device.
