This set of Refrigeration Multiple Choice Questions & Answers (MCQs) focuses on “Expansion Devices”.
1. The device which divides the high pressure side and the low pressure side of a refrigerating system is known as _____________
a) condenser device
b) evaporator device
c) receiver device
d) expansion device
View Answer
Explanation: The expansion device is an important device that divides the high pressure side and the low pressure side of a refrigerating system. It is also known as metering device or throttling device.
2. Which of the following function is not performed by the expansion device?
a) It reduces the high pressure liquid refrigerant to low pressure liquid refrigerant
b) It maintains the desired pressure difference between the high and low pressure sides of the system
c) It controls the flow of refrigerant according to the load on the evaporator
d) It compresses the vapor
View Answer
Explanation: The expansion device performs the following functions, it reduces the high pressure liquid refrigerant to low pressure liquid refrigerant, it maintains the desired pressure difference between the high and low pressure sides of the system and It controls the flow of refrigerant according to the load on the evaporator.
3. The expansion device used with flooded evaporators is known as expansion valves.
a) True
b) False
View Answer
Explanation: The expansion device used with flooded evaporators is known as float valves and the expansion device used with dry expansion evaporators are called expansion valves.
4. The expansion device is placed between which two components?
a) Condenser and evaporator
b) Compressor and condenser
c) Evaporator and compressor
d) Receiver and evaporator
View Answer
Explanation: The expansion device is placed between receiver (containing liquid refrigerant at high pressure) and evaporator (containing liquid refrigerant at low pressure).
5. Which of the following is not an advantage of capillary tube?
a) The cost of capillary tube is less
b) A high starting motor is not required
c) No receiver is needed
d) A capillary tube designed for a specific condition will also work efficiently for other conditions
View Answer
Explanation: A capillary tube designed for a specific condition will not work efficiently for other conditions as the length is directly and inner diameter is indirectly proportional to the frictional resistance. The longer the tube and smaller the diameter, greater is the pressure drop created in the refrigerant flow.
6. Capillary tube, as an expansion device is used in?
a) Water coolers
b) Domestic refrigerators
c) Room air conditioners
d) All of the mentioned
View Answer
Explanation: The capillary tube as an expansion device is used in small capacity hermetic sealed refrigeration units such as in water coolers, domestic refrigerators and room air conditioners, etc.
7. Which one of the following is also known as a constant superheat valve?
a) Capillary tube
b) Hand-operated expansion valve
c) Thermostatic Expansion valve
d) Low side float valve
View Answer
Explanation: Thermostatic expansion valve is also called a constant superheat valve because it maintains a constant superheat of the vapor refrigerant at the end of the evaporator coil, by controlling the flow of liquid refrigerant through the evaporator.
8. Thermostatic expansion valves are usually set for a superheat of?
a) 10°C
b) 5°C
c) 8°C
d) 15°C
View Answer
Explanation: Thermostatic expansion valves are usually set for a superheat of 5°C for better efficiency of the refrigeration cycle.
9. The low-side float valve is located between the condenser and evaporator.
a) True
b) False
View Answer
Explanation: The low-side float valve is located in the low pressure side i.e. between the evaporator and the compressor suction line. Whereas the high side float valve is located in the high pressure side i.e. between the condenser and evaporator.
10. The thermostatic expansion valve operates on the changes in the ___________
a) degree of superheat at exit from the evaporator
b) temperature of the evaporator
c) pressure in the condenser
d) pressure in the evaporator
View Answer
Explanation: The thermostatic expansion valve operates on the changes in the degree of superheat at exit from the evaporator. Thermostatic expansion valves are usually set for a superheat of 5° C for better efficiency of the refrigeration cycle.
Sanfoundry Global Education & Learning Series – Refrigeration & Air Conditioning.
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