What is the primary purpose of refrigeration?
A
To heat a space B
To reduce the temperature and maintain it below ambient C
To humidify air D
To remove moisture only
Analysis & Theory
Refrigeration is mainly used to lower and maintain temperature below surroundings.
Which of the following is a common method of refrigeration?
A
Compression refrigeration B
Condensation heating C
Thermal expansion heating D
Friction cooling
Analysis & Theory
Compression refrigeration is widely used in domestic and industrial applications.
In a vapor compression refrigeration system, the refrigerant changes phase in:
A
The compressor only B
The condenser and evaporator C
The expansion valve only D
The receiver tank
Analysis & Theory
The refrigerant evaporates in the evaporator and condenses in the condenser.
Which component in the vapor compression cycle absorbs heat from the refrigerated space?
A
Compressor B
Condenser C
Evaporator D
Expansion valve
Analysis & Theory
The evaporator absorbs heat from the space to be cooled.
Absorption refrigeration typically uses which working pair?
A
Water and ammonia B
Hydrogen and oxygen C
Nitrogen and argon D
Freon and methane
Analysis & Theory
Ammonia-water systems are commonly used in absorption refrigeration.
Which of the following is NOT a method of refrigeration?
A
Thermoelectric refrigeration B
Vapor compression refrigeration C
Absorption refrigeration D
Direct combustion cooling
Analysis & Theory
Direct combustion cooling does not exist as a refrigeration method.
Thermoelectric refrigeration works on the principle of:
A
Peltier effect B
Joule heating C
Carnot cycle D
Bernoulli's principle
Analysis & Theory
Thermoelectric refrigeration uses the Peltier effect to create cooling.
Which of the following refrigeration methods has no moving parts?
A
Vapor compression B
Absorption C
Thermoelectric D
Gas refrigeration
Analysis & Theory
Thermoelectric refrigeration has no moving mechanical components.
In gas refrigeration systems, cooling is achieved by:
A
Compressing and condensing gas B
Expanding a high-pressure gas to a lower pressure C
Using chemical absorption D
Applying electrical current directly
Analysis & Theory
Cooling happens due to expansion of gas, reducing its temperature.
Which method of refrigeration is commonly used in domestic refrigerators?
A
Vapor compression B
Gas refrigeration C
Thermoelectric D
Magnetic refrigeration
Analysis & Theory
Vapor compression refrigeration is the standard method in household refrigerators.