Food Engineering

Unit Operations

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Ratio of equilibrium concentrations of solute A in liquid phase and gas phase i.e. CAL* and CAg* respectively is α. α is called _____
Diffusion coefficient
Distribution coefficient
Mass transfer coefficient
None of the mentioned
Explanation:
CAL*/CAg* = α = Distribution coefficient.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is NOT an important criteria for crystal formation?
Caking characteristics of the crystal
Moisture content
Shape
None of the mentioned
Explanation:
All the mentioned factors are important criteria for the formation of crystals.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: Duhring’s rule states that the ratio of temperatures at which two solutions have the same vapor pressure is constant.
True, False
True, True
False, False
False, True
Explanation:
Both the statements are true. Duhring’s rule is stated in both ways.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Which of the following factor does the rate of filtration depend on?
Compressibility factor of the filtrate
Pressure drop
Compressibility factor of the filtrate & Pressure drop
Neither of the mentioned
Explanation:
Rate of filtration depends on both of the mentioned factors.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which of the following sentences is true?
Direct heating has higher heat transfer rates than indirect heating
Indirect heating has higher heat transfer rates than direct heating
Both of them have the same heat transfer rates
Cannot be determined
Explanation:
Direct heating has higher heat transfer rates than indirect heating.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
This method is used in food processing for removal of bad odours from food.
Flash distillation
Steam distillation
Batch distillation
Gas adsorption
Explanation:
Steam distillation is used in food processing for removal of bad odours from food.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
A food industry keeps food cool in a very crude manner, by radiation. It paints its walls white and not black, because of _____
Kirchhoff’s Law
Stephan-Boltzmann Law
None of the mentioned
Kirchhoff’s Law & Stephan-Boltzmann Law
Explanation:
Kirchhoff’s law states that at temperature equilibrium, the absorptivity of a grey body is equal to its emissivity. Since white paint has less emissivity than that of black paint, the wall is painted white.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Stationary screens can be used for wet particles.
True
False
Explanation:
Stationary screens only rely upon gravity for the settling and movement of particles from one screen to another. Hence they cannot be used for wet particles.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: It is generally not possible to change the direction of flow with belt conveyors.
True, False
True, True
False, False
False, True
Explanation:
It is generally not possible to change the direction of flow with belt conveyors. If belt conveyors are to be used in the bent position, slat belts are used.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: Blood is a _____
Newtonian fluid, False
Rheopectic, True
Pseudo plastic, False
Casson plastic, True
Explanation:
Blood is a Casson plastic. At low shears, they’ve infinite viscosity. At high shears, its viscosity decreases with increase in shear. Statement 2 is true.