Food Engineering Questions and Answers – Unit Operations – Evaporation-1

This set of Food Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Unit Operations – Evaporation-1”.

1. Statement 1: Evaporation is considered a mass and heat transfer operation.
Statement 2: After evaporation, solids are left behind.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer

2. During evaporation of edible solutions, the BPR-boiling point rise should be _____ and the foaming and scale formation should be _____
a) Low, minimum
b) High, maximum
c) Low, maximum
d) High, minimum
View Answer

3. Which of the following is true while concentrating jams?
a) They’re sensitive to heat
b) Evaporation process for jams is carried out under vacuum
c) At vacuum, the boiling point decreases
d) All of the mentioned
View Answer

4. Statement 1: Boiling point rise is due to the colligative properties due to the presence of solid particles in the solvent.
Statement 2: Boiling point rise is due to the increase in pressure at the bottom of the solvent due to hydro-static head of the column.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer

5. Statement 1: Duhring’s rule states that the ratio of temperatures at which two solutions have the same vapor pressure is constant.
Statement 2: Duhring’s rule states that the boiling point of a solution is a linear function of the boiling point of pure water at the same pressure.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer

6. Statement 1: In a multiple effect evaporator, the overall temperature drop is equal to the individual drops at each step.
Statement 2: In a multiple effect evaporator, the total area is equal to the sum of the individual areas.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer

7. Statement 1: Forward feeding requires pumps for the feed at every step.
Statement 2: In a backward feeding arrangement, the most concentrated feed is exposed to the maximum steam in order to remove heat. This is its advantage.
a) True, False
b) True, True
c) False, False
d) False, True
View Answer

8. One disadvantage with backward feeding is that the feed gets very concentrated at the beginning few units itself and hence it’s difficult to feed it to the next evaporator unit.
a) True
b) False
View Answer

9. Mixed feed arrangement offers the advantage of omitting the usage of pumps by transferring feed in the direction of low pressure. That’s an advantage taken from forward feeding arrangement.
a) True
b) False
View Answer

10. At a food processing industry, the steam was re-compressed and a small amount of steam at high pressures and temperatures was sent into the next evaporation chamber in a multiple effect evaporator. Which of the following is true with respect to the above sentences?
a) There might be wear and tear in the evaporator
b) The overall pressure and temperature of steam increases which is desired
c) The capacity of the evaporator increases
d) All of the mentioned
View Answer

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.