MCQOPTIONS
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MCQOPTIONS
This section includes 28 Mcqs, each offering curated multiple-choice questions to sharpen your Mass Transfer knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Heat transfer takes place as per ______________ |
| A. | Zeroth law of thermodynamics |
| B. | First law of thermodynamics |
| C. | Second law of thermodynamics |
| D. | Kirchoff’s law |
| Answer» D. Kirchoff’s law | |
| 2. |
Which is the fastest mode of transfer of heat? |
| A. | Conduction |
| B. | Convection |
| C. | Scattering |
| D. | Radiation |
| Answer» E. | |
| 3. |
Convection is faster than conduction? |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4. |
A stream of air at 100 kPa pressure and 300 K is flowing on the top surface of a thin flat sheet of solid naphthalene of length 0.2 m with a velocity of 20 m/sec. The other data are:Mass diffusivity of naphthalene vapor in air = 6 * 10 –6 m2/secKinematic viscosity of air = 1.5 * 10 –5 m2.scConcentration of naphthalene at the air-solid naphthalene interface = 1 * 10 – 5 kmol/m3Calculate the overage mass transfer coefficient over the flat plate.Note: For heat transfer over a flat plate, convective heat transfer coefficient for laminar flow can be calculated by the equation.Nu = 0.664 ReL1/2 Pr1/3you may use analogy between mass and heat transfer. |
| A. | 0.014 m/sec |
| B. | 0.015 m/sec |
| C. | 0.016 m/sec |
| D. | 0.013 m/sec |
| Answer» B. 0.015 m/sec | |
| 5. |
In a wetted-wall tower, an air-H2S mixture is flowing by a film of water which is flowing as a thin film down a vertical plate. The H2S is being absorbed from the air to the water at a total pressure of 1.50 atm abs and 30oC. The value of kc of 9.567×10-4 m/s has been predicted for the gas-phase mass-transfer coefficient. At a given point the mole fraction of H2S in the liquid at the liquid-gas interface is 2.0×10-5 and pA of H2S in the gas is 0.05 atm. The Henry’s law equilibrium relation is pA(atm) = 609xA (mole fraction in liquid). Calculate the rate of absorption of H2S. |
| A. | 1.480×10-3 kmol/m2.s |
| B. | 1.486×10-3 kmol/m2.s |
| C. | 1.485×10-3 kmol/m2.s |
| D. | . Calculate the rate of absorption of H2S.a) 1.480×10-3 kmol/m2.sb) 1.486×10-3 kmol/m2.sc) 1.485×10-3 kmol/m2.sd) 1.487×10-3 kmol/m2.s |
| Answer» C. 1.485×10-3 kmol/m2.s | |
| 6. |
Convection does not occur in _______________ |
| A. | Solid |
| B. | Liquid |
| C. | Gas |
| D. | Molten Solid |
| Answer» B. Liquid | |
| 7. |
Which number forms the connecting link between the temperature and concentration profiles? |
| A. | Prandtl number |
| B. | Schmidt number |
| C. | Fourier number |
| D. | Lewis number |
| Answer» E. | |
| 8. |
Which number forms the connecting link between the velocity and concentration profiles? |
| A. | Schmidt number |
| B. | Reynolds number |
| C. | Stanton number |
| D. | Fourier number |
| Answer» B. Reynolds number | |
| 9. |
WHICH_NUMBER_FORMS_THE_CONNECTING_LINK_BETWEEN_THE_TEMPERATURE_AND_CONCENTRATION_PROFILES??$ |
| A. | Prandtl number |
| B. | Schmidt number |
| C. | Fourier number |
| D. | Lewis number |
| Answer» E. | |
| 10. |
WHICH_NUMBER_FORMS_THE_CONNECTING_LINK_BETWEEN_THE_VELOCITY_AND_CONCENTRATION_PROFILES??$ |
| A. | Schmidt number |
| B. | Reynolds number |
| C. | Stanton number |
| D. | Fourier number |
| Answer» B. Reynolds number | |
| 11. |
664 ReL1/2 Pr1/3$ |
| A. | |
| B. | 0.014 m/sec |
| C. | 0.015 m/sec |
| Answer» B. 0.014 m/sec | |
| 12. |
Heat transfer by molecular collision in ____________________ |
| A. | Conduction |
| B. | Convection |
| C. | Scattering |
| D. | Radiation |
| Answer» D. Radiation | |
| 13. |
Which type of columns are used for liquid dispersion in a continuous gas phase? |
| A. | Packed |
| B. | Bubble cap |
| C. | Sieve – plate |
| D. | Fluidized bed |
| Answer» E. | |
| 14. |
Psychrometry deals with between which type of phases? |
| A. | Gas-liquid |
| B. | Gas-solid |
| C. | Gas-Vapour |
| D. | Vapour-Solid |
| Answer» B. Gas-solid | |
| 15. |
Refer to Q8 and, calculate the rate of loss of naphthalene from the surface per unit width. |
| A. | 0.100 gmol/m.hr |
| B. | 0.102 gmol/m.hr |
| C. | 0.101 gmol/m.hr |
| D. | 0.103 gmol/m.hr |
| Answer» C. 0.101 gmol/m.hr | |
| 16. |
Which number forms the connecting link between the velocity and temperature profiles? |
| A. | Fourier number |
| B. | Prandtl number |
| C. | Stanton number |
| D. | Biot number |
| Answer» C. Stanton number | |
| 17. |
What do you mean by Sherwood number? |
| A. | Dimension mass transfer number |
| B. | Dimensionless mass transfer number |
| C. | Dimension momentum transfer number |
| D. | Dimensionless momentum transfer number |
| Answer» C. Dimension momentum transfer number | |
| 18. |
Convective mass transfer involves the transportation of material between a boundary surface and a moving fluid or between two immiscible fluids. It is prescribed by the relation |
| A. | 2 h <sub>m </sub>(d C <sub>B</sub>) |
| B. | ¬Ω h <sub>m </sub>(d C <sub>B</sub>) |
| C. | h <sub>m </sub>(d C <sub>B</sub>) |
| D. | 3/2 h <sub>m </sub>(d C <sub>B</sub>) |
| Answer» D. 3/2 h <sub>m </sub>(d C <sub>B</sub>) | |
| 19. |
In a wetted-wall tower, an air-H2S mixture is flowing by a film of water which is flowing as a thin film down a vertical plate. The H2S is being absorbed from the air to the water at a total pressure of 1.50 atm abs and 30oC. The value of kc of 9.567×10-4 m/s has been predicted for the gas-phase mass-transfer coefficient. At a given point the mole fraction of H2S in the liquid at the liquid-gas interface is 2.0×10-5 and pA of H2S in the gas is 0.05 atm. The Henry’s law equilibrium relation is pA(atm) = 609xA (mole fraction in liquid). Calculate the rate of absorption of H2S.$ |
| A. | 1.480√ó10-3 kmol/m<sup>2</sup>.s |
| B. | 1.486√ó10-3 kmol/m<sup>2</sup>.s |
| C. | 1.485√ó10-3 kmol/m<sup>2</sup>.s |
| D. | 1.487√ó10-3 kmol/m<sup>2</sup>.s |
| Answer» C. 1.485‚Äö√†√∂‚àö‚â•10-3 kmol/m<sup>2</sup>.s | |
| 20. |
The solution for velocity, concentration and temperature boundary layers will be same if |
| A. | Prandtl number = Schmidt number= Lewis number |
| B. | Prandtl number = 2 Schmidt number= Lewis number |
| C. | Prandtl number = Schmidt number= 2 Lewis number |
| D. | 2 Prandtl number = Schmidt number= Lewis number |
| Answer» B. Prandtl number = 2 Schmidt number= Lewis number | |
| 21. |
The distribution coefficient is accurate only if? |
| A. | Solvents are miscible |
| B. | Solutes are miscible |
| C. | Solvents are immiscible |
| D. | Occurrence of chemical reaction |
| Answer» D. Occurrence of chemical reaction | |
| 22. |
Sherwood number is given by |
| A. | 3/2 h <sub>m </sub>L/D |
| B. | ¬Ω h <sub>m </sub>L/D |
| C. | 3 h <sub>m </sub>L/D |
| D. | h <sub>m </sub>L/D |
| Answer» E. | |
| 23. |
In the two-phase aqueous systems, in ordinary situations the bulk phases are not in equilibrium? |
| A. | True |
| B. | False |
| Answer» B. False | |
| 24. |
Rate of mass transfer is inversely proportional to the rate of reaction at solid surface? |
| A. | True |
| B. | False |
| Answer» C. | |
| 25. |
Prandtl number is given by |
| A. | V/α |
| B. | 2 V/α |
| C. | 3 V/α |
| D. | 4 V/α |
| Answer» B. 2 V/‚âà√≠¬¨¬± | |
| 26. |
The unit of mass transfer coefficient is ______________ |
| A. | m<sup>-1</sup>s |
| B. | ms<sup>-1</sup> |
| C. | m<sup>-1</sup>s<sup>2</sup> |
| D. | m<sup>2</sup>s<sup>-1</sup> |
| Answer» C. m<sup>-1</sup>s<sup>2</sup> | |
| 27. |
Lewis number is given by |
| A. | 4 α/D |
| B. | 3 α/D |
| C. | 2 α/D |
| D. | α/D |
| Answer» E. | |
| 28. |
The mass transfer by convection can take place under how many conditions? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |