This set of Food Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Unit Operations – Heat Transfer Equipment”.
1. Which of the following sentences is true?
a) Direct heating has higher heat transfer rates than indirect heating
b) Indirect heating has higher heat transfer rates than direct heating
c) Both of them have the same heat transfer rates
d) Cannot be determined
View Answer
Explanation: Direct heating has higher heat transfer rates than indirect heating.
2. If _______ heating has higher heat transfer rates than _______ heating, then why is ________ difficult to be used.
a) Direct, Indirect, no difficulty, they’re used
b) Direct, Indirect, coil is difficult to clean and is prone to bacterial growth
c) Indirect, Direct, no difficulty, they’re used
d) Indirect, Direct, coil is difficult to clean and is prone to bacterial growth
View Answer
Explanation: Direct heating has higher heat transfer rates than indirect heating, but, the coil is difficult to clean and is prone to bacterial growth.
3. In a jacketed vessel, the only way to increase the heat transfer rates is to increase the temperature difference.
a) True
b) False
View Answer
Explanation: In a jacketed vessel, the only way to increase the heat transfer rates is to increase the temperature difference.
4. Which of the following is an advantage of using pumps as heat transfer equipment?
a) No stirrer required
b) Taking them to a heat exchanger where the area used for heat transfer can be easily changed
c) No stirrer required & taking them to a heat exchanger where the area used for heat transfer can be easily changed
d) None of the mentioned
View Answer
Explanation: Both the mentioned statements are true.
5. External heat exchangers are gaining popularity as they’ve several advantages over conventional methods. Still, there is a major drawback. Which among the following is it?
a) Some shear-sensitive cells might get damaged due to abrasion
b) It is difficult for pumps to withstand high temperature without leakages of the fluid
c) All of the mentioned
d) None of the mentioned
View Answer
Explanation: External heat exchangers are gaining popularity as they’ve several advantages over conventional methods. Still, there are drawbacks like some shear-sensitive cells might get damaged due to abrasion. Also, it is difficult for pumps to withstand high temperature without leakages of the fluid.
6. Which of the following is a parameter to be checked before choosing the shape of the pitch in heat exchangers?
a) Easiness to clean
b) High heat transfer
c) Cost
d) All of the mentioned
View Answer
Explanation: All of the mentioned are valid reasons.
7. Statement 1: Difference between 1-1 and 1-2 heat exchanger is that 1-2 has both counter AND co current, whereas 1-1 has only co-current.
Statement 2: 1-2 heat exchanger requires a high pressure drop.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer
Explanation: Both the statements pertaining to heat exchangers are true.
8. Statement 1: Generally, in small scaled jacketed pans, food products like jams, sauces etc are made.
Statement 2: Baffles provide structural support to tubes, but they cannot prevent channeling.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer
Explanation: Generally, in small scaled jacketed pans, food products like jams, sauces etc are made. Baffles provide structural support to tubes and prevent channeling also.
9. Statement 1: Scraping improves heat transfer co-efficient by 5 times in case of non-Newtonian fluids.
Statement 2: In food industry, major physical changes to food items when they’re processed, take place like transformation from Newtonian to Non-Newtonian fluids. Hence, scraped surface heat exchangers are very beneficial.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer
Explanation: Both the statements are true.
10. Which of the following is untrue about scraped surface heat exchangers?
a) They’re unsuitable for viscous fluids
b) They’re suitable for fouling fluids
c) They’re used for continuous operation and have a double pipe
d) None of the mentioned
View Answer
Explanation: Scraped surface heat exchangers are suitable for viscous fluids.
11. Which of the following heat exchangers are used for the quick exchange of heat?
a) Shell and tube heat exchangers
b) Plate heat exchangers
c) Scraped surface heat exchangers
d) Jacketed Vessels
View Answer
Explanation: Plate heat exchangers are used for the quick exchange of heat.
12. Statement 1: Plate heat exchangers are used in heat sensitive foods like milk.
Statement 2: Principle behind plate heat exchangers is that there is very less space between the plates and hence quick heating can take place.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer
Explanation: Both the statements are true.
13. Which of the following is true about Plate heat exchangers?
a) They’re used for Ultra high temperature treatment
b) Used for high temperature and short time
c) They’re used for Ultra high temperature treatment and also Used for high temperature and short time
d) None of the mentioned
View Answer
Explanation: Plate heat exchangers are used for Ultra high temperature treatment (UHT) and for High temperature and short time (HTST).
14. Contamination takes place to high extend in Plate heat exchangers.
a) True, the space between plates is too less
b) False, they cannot be used for viscous liquids
c) Cannot be determined
d) True, they can be used for thin liquids only
View Answer
Explanation: The space between plates, in a Plate heat exchanger is too less.
15. Statement 1: In coiled heat exchanger, the coils can be present inside and outside the vessel.
Statement 2: The coils can have either hot/cold fluid present inside them or even electrical coils can be present.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer
Explanation: Both the statements are true.
Sanfoundry Global Education & Learning Series – Food Engineering.
To practice all areas of Food Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.
- Check Agricultural Engineering Books
- Apply for Agricultural Engineering Internship
- Practice Agricultural Engineering MCQs
- Check Food Engineering Books