Food Engineering Practice Test 3

1. Statement 1: Considering the equation, μ_a= τ/γ = Kγ^(n-1) , for pseudo plastic fluids, n<1 and they’re called Shear thinning liquids and dilatant fluids are called Shear thickening liquids as n>1.
Statement 2: Cooked starch solution is a Shear thinning liquid and dairy cream is a Shear thickening liquid.

False, False

True, False

True, True

False, True

2. Statement 1: Apparent viscosity μ_a is related to shear stress (τ) and shear strain (γ) as μ_a= τ/γ.
Statement 2: The equation τ=Kγⁿ becomes μ_a= τ/γ = Kγ^(n-1) .

False, False

True, False

False, True

True, True

3. Since excess UV-C causes DNA damage, which of the following methods can be used to apply this technique itself in spite of this drawback?

All of the mentioned

Reduce the exposure time to this process by combining two or more methods

None of the mentioned

There is no solution

4. Statement 1: In nusselt’s film theory, velocity of the falling film is not affected by the velocity of the vapors.
Statement 2: LMTD can be used provided the overall heat transfer co-efficient is constant over a large range of temperatures.

True, True

False, False

True, False

False, True

5. Statement 1: Pulsed Electric field needs to followed by refrigeration storing to increase shelf life and prevent spoilage.
Statement 2: Structural changes at cell membrane and inactivation of enzymes, is how high hydrostatic pressure works for the food industry.

True, True

True, False

False, False

False, True

6. Which of the following holds true for Pulsed Electric field?

It has been successful in pasteurizing milk, yogurt, soup etc

All of the mentioned

If there are no air bubbles present or the if food has low electrical conductivity, PEF is non-applicable

It’s a continuous process. It cannot be applied for non-pump able solid food products

7. _____ is the equation for unsteady state heat conduction through solid materials.

dT/dx= α (d² T)/ (dx)²

dT/dt= α (d² T)/ (dt)²

dT/dx= α (d² T)/ (dt)²

dT/dt= α (d² T)/ (dx)²

8. Statement 1: For rough control of flow _____ are used.
Statement 2: For fine control of flow _____ are used.

Needle valves, Gate valves

Needle valves, Globe valves

Globe valves, Needle valves

Gate valves, Globe valves

9. Which of the following is NOT a real dimensionless number?

Stanton number

Pectit number

Graetz number

Grashof number

10. Which of the following is true about turmeric?

After drying, the turmeric hardens up

Green rhizomes are boiled in water till a froth comes out and white fumes appear giving out a characteristic odour

The softness of the cooked rhizomes depends on the curing conditions and process

All of the mentioned