MCQOPTIONS
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MCQOPTIONS
This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer Operations knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which one of the following is correct expression for sphericity of a particle?
|
| A. | S = ( frac{6Vp}{Ap} ) |
| B. | S = ( frac{ pi^{ frac{1}{3}}(6Vp)^ frac{2}{3}}{Ap} ) |
| C. | S = ( frac{ pi^{ frac{1}{3}}(6Vp)^ frac{4}{3}}{Ap} ) |
| D. | S = ( frac{(6Vp)^ frac{2}{3}}{Ap} ) |
| Answer» C. S = ( frac{ pi^{ frac{1}{3}}(6Vp)^ frac{4}{3}}{Ap} ) | |
| 2. |
What is the term in the Kozeny Carman equation for laminar flow in packed beds?
|
| A. | Surface Area of pellets |
| B. | Sphericity of Pellets |
| C. | Void fraction |
| D. | Density |
| Answer» C. Void fraction | |
| 3. |
A fully packed bed with small particle size has _________ pressure drop than a bed with larger particle size. |
| A. | More |
| B. | Less |
| C. | Same |
| D. | Negligible |
| Answer» B. Less | |
| 4. |
Which one of the following is the correct expression for Friction Factor in Packed Bed Columns? |
| A. | f = 150/Re |
| B. | f = 150/Re+1.75 |
| C. | f = 180/Re+1.5 |
| D. | f = 100/Re+0.0035 |
| Answer» C. f = 180/Re+1.5 | |
| 5. |
In the Formula for porosity, what is the meaning of the term V?
|
| A. | Volume of Void |
| B. | Volume of Pure Solid |
| C. | Total Volume |
| D. | Volume of the tube material |
| Answer» B. Volume of Pure Solid | |
| 6. |
What is the relation between superficial velocity and average fluid velocity in a packed bed? |
| A. | ϑ= u |
| B. | ϑ=u/ |
| C. | &vartheta;= <sup>0.14</sup>u |
| D. | &vartheta;= (^ frac{ vartheta}{u}u ) |
| Answer» B. &vartheta;=u/ | |
| 7. |
If we have a tube of diameter 30mm and particles of diameter 3mm, the length of the tube is 10cm and the number of pellets is 100. The flow rate is 5cm3/s, then what is the superficial velocity? |
| A. | 0.5cm/s |
| B. | 0.45cm/s |
| C. | 0.7cm/s |
| D. | 0.8cm/s |
| Answer» D. 0.8cm/s | |
| 8. |
If we have a tube of diameter 30mm and particles of diameter 2mm, the length of the tube is 10cm and the number of pellets is 100. Then what is the porosity? |
| A. | 0.45 |
| B. | 0.95 |
| C. | 0.99 |
| D. | 0.65 |
| Answer» D. 0.65 | |
| 9. |
If we have very small dp/di < 0.01, then we may use ____________ |
| A. | Ergun Equation |
| B. | Kozeny Carman Equation |
| C. | Sieder Tate Equation |
| D. | Arrhenius Equation |
| Answer» C. Sieder Tate Equation | |
| 10. |
In the Ergun equation, what do you understand by the term X?
|
| A. | Diameter of the tube |
| B. | Diameter of the pellets |
| C. | Effective diameter |
| D. | Equivalent diameter of the tube |
| Answer» C. Effective diameter | |
| 11. |
The Ergun equation is used to calculate the ___________ |
| A. | Pressure drop in packed beds |
| B. | Reynolds number in packed columns |
| C. | Overall heat transfer coefficients |
| D. | Number of particles |
| Answer» B. Reynolds number in packed columns | |