This set of Fruits Processing Multiple Choice Questions & Answers (MCQs) focuses on “Refrigeration of Fruits”.
1. What is the difference between freezing and refrigeration?
a) Only the temperature
b) Only the pressure
c) Only the energy consumption
d) Temperature, pressure and energy consumption
View Answer
Explanation: In refrigeration, food is stored between temperatures of 3-7 degrees Celsius which are slightly higher than the sub-zero temperatures of the freezer. Freezing causes the water in the food is converted into ice. The ice is not formed during refrigeration.
2. What is the process of refrigeration?
a) Removal of unwanted heat from the product
b) Addition of heat to the product
c) Removal of moisture from the product
d) Addition of moisture to the product
View Answer
Explanation: Refrigeration is a low temperature process which cools down the product. The heat is removed from the product and is transfer to cooling medium. This removal of heat process decreases the temperature. Generally, ice chilled water or refrigeration medium are used as cooling medium.
3. Which cycle is used in refrigeration?
a) Vapor-compression refrigeration cycle
b) Compression refrigeration cycle
c) Vapor refrigeration cycle
d) Evaporative refrigeration cycle
View Answer
Explanation: The most commonly used refrigeration cycle is the vapor-compression refrigeration cycle. In an ideal vapor-compression refrigeration cycle, the refrigerant moves in the compressor as a saturated vapor and is cooled to the saturated liquid state in the condenser.
4. What is chiller approach?
a) Difference between the leaving water temperature and the saturated refrigerant temperature
b) Ratio between the leaving water temperature and the saturated refrigerant temperature
c) Difference between the saturated refrigerant temperature and water temperature
d) Ratio between the saturated refrigerant temperature and water temperature
View Answer
Explanation: Chiller approach is the difference in temperature between the leaving water temperature and the saturated refrigerant temperature. A normal evaporator approach temperature on a flooded chiller is between 0-2°C.The DX chiller approach temperature is between 3-5°C.
5. Is a higher COP better?
a) True
b) False
View Answer
Explanation: The coefficient of performance or COP is a ratio of useful heating or cooling provided to work required. The higher the COP, the more efficient the machine operates and low performance coefficient generally have negative impact on the machine’s operating cost.
6. Can coefficient of performance be more than1?
a) True
b) False
View Answer
Explanation: Coefficient of performance is always more than 1. COP (coefficient of performance) is the ratio of heat extracted from the refrigerator to the work done on the refrigerant. Thus, the value of COP is bound to be greater than unity since efficiency is always less than 1.
7. Who invented refrigerator?
a) Oliver Evans
b) William Cullen
c) Nicolas Appert
d) Jacob Parkins
View Answer
Explanation: William Cullen invented refrigerator. Oliver Evans designed refrigerator. Nicolas Appert is the father of food processing. Jacob Parkins built the first machine for practical refrigeration.
8. What is the full from of COP?
a) Coefficient of performance
b) Coefficient of power
c) Constant of performance
d) Constant of power
View Answer
Explanation: The efficiency of refrigeration systems and heat pumps is denoted by its coefficient of performance. The COP usually exceeds 1, especially in heat pumps, because, instead of converting work to heat, it pumps additional heat from a heat source to where the heat is required.
9. Why is compressor used in refrigerator?
a) To maintain low pressure
b) To maintain high pressure
c) To maintain constant temperature
d) To maintain high temperature
View Answer
Explanation: The compressor works as a pump to control the circulation of the refrigerant it also adds pressure to the refrigerant, heating it up. The compressor also draws vapor away from the evaporator to maintain a lower pressure and lower temperature before sending it to the condenser.
10. Which oil is used in refrigerator compressor?
a) Polyolester oil
b) Polyether oil
c) Polyester oil
d) Polyether oil and polyester oil
View Answer
Explanation: Polyolester oil (POE oil) is a type of synthetic oil used in refrigeration compressors. It is compatible with the refrigerants R-134a, R-410A and R-12. It is recommended by experts as a replacement for hydrofluorocarbons (HFCs).
11. Why is condenser used in refrigerator?
a) To maintain low pressure
b) To maintain high pressure
c) To maintain low temperature
d) To maintain high temperature
View Answer
Explanation: In the condenser, a fan blows across the coils cooling the gas and releasing the heat out of the refrigerator to the outside. As the heat is released, the refrigerant turns back into a liquid. The liquid then flows to an expansion device that regulates the flow of the refrigerant.
Sanfoundry Global Education & Learning Series – Fruits Processing.
To practice all areas of Fruits Processing, here is complete set of 1000+ Multiple Choice Questions and Answers.
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