ABSA 4b Exam 2025 | Actual Exam Questions and
Correct Answers | Graded A+ | Verified Answers |
Latest Exam
Which of the following statements about the economisers is
false?
a) It controls the flow of liquid refrigerant from the low
pressure evaporator to the high pressure condenser.
b) It is composed of two chambers.
c) The upper float chamber is connected to the bottom of the
condenser.
d) The economiser float chamber is connected via the motor
to the second stage inlet of the compressor.
e) Liquid refrigerant levels in each chamber are controlled
by a float operated valve in the evaporator. ---------CORRECT ANSWER----------------
-A
Which of the following is a result of an economiser on the
refrigeration system?
a) an intercooling effect on the compressor
b) reduction of the power required for compression in the
second stage compressor
c) reduction of flash vapour in the evaporator
,d) increase in the refrigerating capacity of a system
e) all of the above ---------CORRECT ANSWER-----------------E
In actual systems there will be a gradual pressure drop
through each side of the system due to
a) the economiser
b) friction in the evaporator, condenser, and piping
c) decomposition of refrigerants
d) coefficients of expansion of system components
e) superheating effects
Refrigeration Compressors ---------CORRECT ANSWER-----------------B
Which of the following is not a function of the compressor in
a refrigeration system?
a) draw low pressure refrigerant out of the evaporator
b) draw low temperature refrigerant out of the evaporator
c) lower the temperature of the refrigerant
d) maintain sufficiently low pressure in the evaporator
e) raise the pressure of the refrigerant ---------CORRECT ANSWER-----------------C
Which of the following is the compressor responsible for
,doing?
i) Maintains a high pressure in the condenser
ii) Maintains a low pressure in the evaporator
iii) Raises the pressure of the refrigerant
a) i only
b) both i and iii
c) both ii and iii
d) iii only
e) i, ii, and iii ---------CORRECT ANSWER-----------------E
In a refrigeration system, the purpose of the compressor is to
a) establish two pressure levels
b) reject the heat from the system
c) absorb the heat into the system
d) regulate the flow of the refrigerant
e) heat the refrigerant ---------CORRECT ANSWER-----------------A
Which of the following compressor types uses impellers to
draw in vapour?
a) Centrifugal compressors
b) Rotary compressors
c) Reciprocating Compressors
, d) None of the above
e) All of the above ---------CORRECT ANSWER-----------------A
One negative factor of Hermetic type reciprocating
compressors is
a) the compressor and motor are mounted within the same
housing
b) the motor is cooled by the low pressure, low temperature
vapour being drawn into the housing
c) it does not have or require shaft sealing
d) field servicing is not possible
e) the compressor is driven by an electric motor ---------CORRECT ANSWER-----------
------D
In a rotating vane design rotary compressor, a good seal is
maintained between the vanes and the cylinder by
a) centrifugal force
b) the oil
c) high pressure refrigerant vapour
d) low pressure suction
e) the eccentric rotor size ---------CORRECT ANSWER-----------------A
Correct Answers | Graded A+ | Verified Answers |
Latest Exam
Which of the following statements about the economisers is
false?
a) It controls the flow of liquid refrigerant from the low
pressure evaporator to the high pressure condenser.
b) It is composed of two chambers.
c) The upper float chamber is connected to the bottom of the
condenser.
d) The economiser float chamber is connected via the motor
to the second stage inlet of the compressor.
e) Liquid refrigerant levels in each chamber are controlled
by a float operated valve in the evaporator. ---------CORRECT ANSWER----------------
-A
Which of the following is a result of an economiser on the
refrigeration system?
a) an intercooling effect on the compressor
b) reduction of the power required for compression in the
second stage compressor
c) reduction of flash vapour in the evaporator
,d) increase in the refrigerating capacity of a system
e) all of the above ---------CORRECT ANSWER-----------------E
In actual systems there will be a gradual pressure drop
through each side of the system due to
a) the economiser
b) friction in the evaporator, condenser, and piping
c) decomposition of refrigerants
d) coefficients of expansion of system components
e) superheating effects
Refrigeration Compressors ---------CORRECT ANSWER-----------------B
Which of the following is not a function of the compressor in
a refrigeration system?
a) draw low pressure refrigerant out of the evaporator
b) draw low temperature refrigerant out of the evaporator
c) lower the temperature of the refrigerant
d) maintain sufficiently low pressure in the evaporator
e) raise the pressure of the refrigerant ---------CORRECT ANSWER-----------------C
Which of the following is the compressor responsible for
,doing?
i) Maintains a high pressure in the condenser
ii) Maintains a low pressure in the evaporator
iii) Raises the pressure of the refrigerant
a) i only
b) both i and iii
c) both ii and iii
d) iii only
e) i, ii, and iii ---------CORRECT ANSWER-----------------E
In a refrigeration system, the purpose of the compressor is to
a) establish two pressure levels
b) reject the heat from the system
c) absorb the heat into the system
d) regulate the flow of the refrigerant
e) heat the refrigerant ---------CORRECT ANSWER-----------------A
Which of the following compressor types uses impellers to
draw in vapour?
a) Centrifugal compressors
b) Rotary compressors
c) Reciprocating Compressors
, d) None of the above
e) All of the above ---------CORRECT ANSWER-----------------A
One negative factor of Hermetic type reciprocating
compressors is
a) the compressor and motor are mounted within the same
housing
b) the motor is cooled by the low pressure, low temperature
vapour being drawn into the housing
c) it does not have or require shaft sealing
d) field servicing is not possible
e) the compressor is driven by an electric motor ---------CORRECT ANSWER-----------
------D
In a rotating vane design rotary compressor, a good seal is
maintained between the vanes and the cylinder by
a) centrifugal force
b) the oil
c) high pressure refrigerant vapour
d) low pressure suction
e) the eccentric rotor size ---------CORRECT ANSWER-----------------A
