MCQOPTIONS
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MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The free convection coefficient is given byh = C 1 d t m/l 1 – 3mThe value of exponent for turbulent flow is |
| A. | 0.43 |
| B. | 0.33 |
| C. | 0.23 |
| D. | 0.13 |
| Answer» C. 0.23 | |
| 2. |
For inclined plates we multiply Grashoff number with |
| A. | Cos 2 α |
| B. | Sin 2 α |
| C. | Sin α |
| D. | Cos α |
| Answer» E. | |
| 3. |
The free convection coefficient is given byh = C 1 d t m/l 1 – 3mThe value of exponent for laminar flow is |
| A. | 0.5 |
| B. | 0.6 |
| C. | 0.7 |
| D. | 0.8 |
| Answer» B. 0.6 | |
| 4. |
A nuclear reactor with its core constructed of parallel vertical plates 2.25 m high and 1.5 m wide has been designed on free convection heating of liquid bismuth. Metallurgical considerations limit the maximum surface temperature of the plate to 975 degree Celsius and the lowest allowable temperature of bismuth is 325 degree Celsius. Estimate the maximum possible heat dissipation from both sides of each plate. The appropriate correlation for the convection coefficient isNu = 0.13 (Gr Pr) 1/3 |
| A. | 143 MW |
| B. | 153 MW |
| C. | 163 MW |
| D. | 173 MV |
| Answer» C. 163 MW | |
| 5. |
For turbulent flow over a flat plate, the average value of Nusselt number is prescribed by the relationNu = 0.664 (Re) 0.5 (Pr) 0.33Which of the following is then a false statement?The average heat transfer coefficient increases as |
| A. | 1/5 power of plate length |
| B. | 2/3 power of thermal conductivity |
| C. | 1/3 power of specific heat |
| D. | 4/5 power of a free stream velocity |
| E. | 0.5 (Pr) 0.33Which of the following is then a false statement?The average heat transfer coefficient increases asa) 1/5 power of plate lengthb) 2/3 power of thermal conductivityc) 1/3 power of specific heatd) 4/5 power of a free stream velocity |
| Answer» B. 2/3 power of thermal conductivity | |
| 6. |
For laminar flow over a flat plate, the average value of a Nusselt number is prescribed by the relationNu = 0.664 (Re) 0.5 (Pr) 0.33Which of the following is then a false statement? |
| A. | Density has to be increased four times |
| B. | Plate length has to be decreased four times |
| C. | Specific heat has to be increased four times |
| D. | Dynamic viscosity has to be decreased sixteen times |
| E. | 0.5 (Pr) 0.33Which of the following is then a false statement?a) Density has to be increased four timesb) Plate length has to be decreased four timesc) Specific heat has to be increased four timesd) Dynamic viscosity has to be decreased sixteen times |
| Answer» E. 0.5 (Pr) 0.33Which of the following is then a false statement?a) Density has to be increased four timesb) Plate length has to be decreased four timesc) Specific heat has to be increased four timesd) Dynamic viscosity has to be decreased sixteen times | |
| 7. |
FOR_INCLINED_PLATES_WE_MULTIPLY_GRASHOFF_NUMBER_WITH?$ |
| A. | Cos 2 α |
| B. | Sin 2 α |
| C. | Sin α |
| D. | Cos α |
| Answer» E. | |
| 8. |
The_free_convection_coefficient_is_given_by$ |
| A. | |
| B. | |
| Answer» C. | |
| 9. |
The free convection coefficient is given b? |
| A. | |
| B. | |
| Answer» B. | |
| 10. |
Free correction modulus is given by |
| A. | p <sup>2</sup> β g c <sub>P</sub>/µ |
| B. | p <sup>2</sup> β g c <sub>P</sub>/k |
| C. | p <sup>2</sup> β g c <sub>P</sub>/µ k |
| D. | p <sup>2</sup> β g c <sub>P</sub> |
| Answer» D. p <sup>2</sup> ‚âà√≠‚Äö√¢¬ß g c <sub>P</sub> | |
| 11. |
A thin walled duct of 0.5 m diameter has been laid in an atmosphere of quiescent air at 15 degree Celsius and conveys a particular gas at 205 degree Celsius. Base your calculations on one meter length of the duct, estimate the convective coefficient of heat transfer |
| A. | 5.086 W/m<sup>2</sup> K |
| B. | 6.086 W/m<sup>2</sup> K |
| C. | 7.086 W/m<sup>2</sup> K |
| D. | 8.086 W/m<sup>2</sup> K |
| Answer» B. 6.086 W/m<sup>2</sup> K | |
| 12. |
Consider the above problem, find the value of Grashoff number |
| A. | 101.3 * 10 <sup>12</sup> |
| B. | 102.3 * 10 <sup>12</sup> |
| C. | 103.3 * 10 <sup>12</sup> |
| D. | 104.3 * 10 <sup>12</sup> |
| Answer» E. | |
| 13. |
A nuclear reactor with its core constructed of parallel vertical plates 2.25 m high and 1.5 m wide has been designed on free convection heating of liquid bismuth. Metallurgical considerations limit the maximum surface temperature of the plate to 975 degree Celsius and the lowest allowable temperature of bismuth is 325 degree Celsius. Estimate the maximum possible heat dissipation from both sides of each plate. The appropriate correlation for the convection coefficient is |
| A. | <sup>1/3</sup> |
| B. | 143 MW |
| C. | 153 MW |
| D. | 163 MW |
| Answer» C. 153 MW | |
| 14. |
For turbulent flow over a flat plate, the average value of Nusselt number is prescribed by the relation |
| A. | <sup>0.5 </sup>(Pr)<sup> 0.33</sup> |
| B. | |
| Answer» B. | |
| 15. |
The convective heat transfer coefficient in laminar flow over a flat plate |
| A. | Increases with distance |
| B. | Increases if a higher viscosity fluid is used |
| C. | Increases if a denser fluid is used |
| D. | Decreases with increase in free stream velocity |
| Answer» D. Decreases with increase in free stream velocity | |