## NIFTEM-FOOD ENGINEERING-III-ENG 311- midterm + End Semester Question Paper-DEC 2018-5th Sem

*The information shared below is only to get a rough idea of NIFTEM’s end semester question paper pattern. However, questions proportion from the syllabus topics may vary every semester.*

# MIDTERM

**Important points-**

- Time- 1:30 hours
- Total Marks- 50
- Three parts A, B & C, in which Part A is compulsory of (15 marks) having Objective questions, MCQs, Fill in the blanks and matching type questions. Students have to answer the questions from Part-A on the paper itself. Time allotted for Part-A is 25 minutes
- Part B & part C consists of 25 marks and 10 marks respectively. Have to attempt -Part B- 5 questions of 5 marks each & Part C- 1 Questions of 10 marks. Time for Part-B and C is total of 01:05 hours.

**PART B **

**PART B**

### Answer any 5 questions from the following-

**1.** Atmospheric air with a volume flow rate (VFR) of 40 m^{3}/min passes through the humidifier at 48°C and 15% RH for cooling. If water required for humidification is 20kg/hr, determine the relative humidity of outlet air.

( Psat @ 48°C=0.1138, Psat @ 29°C=0.0408, Psat 30°C=0.0431)

**2.** Explain the adiabatic humidification process.

**3.** Prove that D_{AB}=D_{BA}, for Equimolar counter diffusion.

**4.** What are the five steps of leaching. Explain.

**5.** What is a Mixer-settler Battery? Explain with a neat schematic diagram.

**6.** The mixture of He and N2 gas is contained in a pipe at 298K and 1 atm pressure which is constant throughout. At the one end of the pipe at point 1 the partial pressure P_{A1}, of He is 0.6atm and at the other end 0.2m, P_{A2 }is 0.2atm. Calculate the flux of He, at steady state if D_{AB} of He-N_{2} mixture is 0.687 x 10^{-4} m^{2}/s.

**7.** What is the vapour of pure butane at 20°C, if the partial pressure is 698 mmHg in a butane acetone mixture where the mole fraction of acetone is 0.677.

**8. **Explain the effect of the size of particles on the extraction process.

**9. **Explain liquid-liquid phase diagram on the triangular coordinate system where components A and B are partially miscible.

**PART C**

### Answer any 1 question from the following-

**1.** Drive the equation for molecular diffusion through a variable cross-section area for the spherical ball and also calculate the time required to vanish the ball. (Assume all necessary data)

**2. **What are the factors, which affect the leaching process? How solids are prepared for effective leaching?

Draw a schematic leveled diagram of the counter-current leaching process.

**3.** Explain the boiling point diagram and VLE curve, also tell what is relative volatility?

# END SEM

**Important points-**

- Time- 3:00 hours
- Total Marks- 100
- Three parts A, B & C, in which Part A is compulsory of (30 marks) having Objective questions, MCQs, Fill in the blanks and matching type questions. Students have to answer the questions from Part-A on the paper itself. Time allotted for Part-A is 40 minutes
- Part B & part C consists of 40 marks and 30 marks respectively. Part B- 8 questions of 5 marks each & Part C- 3 Questions of 10 marks each. Time for Part-B and C is total of 2:20 hours.

**PART B **

### Answer any 8 questions from the following-

**1.** Explain in brief

A) Osmosis

B) Reverse osmosis.

**2.** Describe any one method to determine the diffusivity coefficient of liquid.

.

**3.** Write the name and equation of any five dimensions less number.

**4.** What is the driving force and resistance in the process of crystallization? Draw a constant pressure solubility curve and explain it.

**5.** Write the complete Reynolds analogy for heat, mass and momentum transfer.

**6.** Express the dimensionless number for the ratio of the shear component for diffusivity µ/ρ to the diffusivity of mass transfer D_{AB}.

**7.** Write down the membrane casting method.

**8. **Define all seven properties of psychrometry.

**9.** How diffusion in solid is different from diffusion in liquid? Explain with suitable example.

**10. **What do you understand by equimolar counter diffusion in the gas phase? Prove D_{AB}=D_{BA}

**PART C**

### Answer any 3 questions from the following-

**1. **Drive the equation for molecular diffusion through a variable cross-section area for uniformly

tapered equilateral rectangular section. (Assume all necessary data).

**2.** A mixture of air and water vapor is contained in a pipe at 25°C and 1 atm total pressure. At one end of the pipe the partial pressure of water vapor is (0.6 atm and at the other end 0.2m away the same is 0.2 atm. Calculate the flux of water vapor from one end to the other. Diffusivity of water vapor in the air is 0.26 cm?/s. How much time it would require to transfer 100kmole of water vapor if the pipe diameter is 10cm.

**3.** Explain any one multistage extraction unit with a neat diagram.

**4.** What is Knudsen diffusion? How it is different from Fickian diffusion. Define the mean free path.

**5.** Explain the different processes using the psychrometric chart.

*Best of Luck !!*

See other papers

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*Source- Question Papers collected and provided by Soumen Roy*

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