MCQOPTIONS
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MCQOPTIONS
This section includes 16 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. |
Consider the above problem, also calculate the temperature at the inside surfaces of the sphere |
| A. | 138.3 degree Celsius |
| B. | 327.8 degree Celsius |
| C. | 254.7 degree Celsius |
| D. | 984.9 degree Celsius |
| Answer» C. 254.7 degree Celsius | |
| 2. |
A hollow sphere (k = 30 W/m K) of inner radius 6 cm and outside radius 8 cm has a heat generation rate of 4000000 W/m3. The inside surface is insulated and heat is removed by convection over the outside surface by a fluid at 100 degree Celsius with surface conductance 300 W/m2 K. Make calculations for the temperature at the outside surfaces of the sphere |
| A. | 105.6 degree Celsius |
| B. | 205.6 degree Celsius |
| C. | 305.6 degree Celsius |
| D. | 405.6 degree Celsius |
| Answer» D. 405.6 degree Celsius | |
| 3. |
Identify the correct boundary condition for a hollow sphere with inside surface insulated |
| A. | At r = r 1, the conduction region is perfectly insulated |
| B. | At r = r 1, the conduction region is partially insulated |
| C. | Heat flow is infinity |
| D. | Heat flow is negative |
| Answer» B. At r = r 1, the conduction region is partially insulated | |
| 4. |
A solid sphere of 8 cm radius has a uniform heat generation 0f 4000000 W/m3. The outside surface is exposed to a fluid at 150 degree Celsius with convective heat transfer coefficient of 750 W/m2 K. If thermal conductivity of the solid material is 30 W/m K, determine maximum temperature |
| A. | 444.45 degree Celsius |
| B. | 434.45 degree Celsius |
| C. | 424.45 degree Celsius |
| D. | 414.45 degree Celsius |
| Answer» C. 424.45 degree Celsius | |
| 5. |
An 8 cm diameter orange, approximately spherical in shape, undergoes ripening process and generates 18000 k J/m3 hr of energy. If external surface of the orange is at 6.5 degree Celsius, find out the temperature at the center of the orange. Take thermal conductivity = 0.8 k J/ m hr degree for the orange material |
| A. | 13.5 degree Celsius |
| B. | 12.5 degree Celsius |
| C. | 11.5 degree Celsius |
| D. | 10.5 degree Celsius |
| Answer» C. 11.5 degree Celsius | |
| 6. |
Consider heat conduction through a solid sphere of radius R. There are certain assumptions(i) Unsteady state conditions(ii) One-dimensional radial conduction(iii) Constant thermal conductivityIdentify the correct statements |
| A. | i and iii |
| B. | ii and iii |
| C. | i, ii and iii |
| D. | i and ii |
| Answer» C. i, ii and iii | |
| 7. |
CONSIDER_THE_ABOVE_PROBLEM,_ALSO_CALCULATE_THE_TEMPERATURE_AT_THE_INSIDE_SURFACES_OF_THE_SPHERE?$ |
| A. | 138.3 degree Celsius |
| B. | 327.8 degree Celsius |
| C. | 254.7 degree Celsius |
| D. | 984.9 degree Celsius |
| Answer» C. 254.7 degree Celsius | |
| 8. |
A hollow sphere (k = 30 W/m K) of inner radius 6 cm and outside radius 8 cm has a heat generation rate of 4000000 W/m3. The inside surface is insulated and heat is removed by convection over the outside surface by a fluid at 100 degree Celsius with surface conductance 300 W/m2 K. Make calculations for the temperature at the outside surfaces of the spher? |
| A. | 105.6 degree Celsius |
| B. | 205.6 degree Celsius |
| C. | 305.6 degree Celsius |
| D. | 405.6 degree Celsius |
| Answer» D. 405.6 degree Celsius | |
| 9. |
Identify the correct boundary condition for a hollow sphere with inside surface insulate? |
| A. | At r = r <sub>1</sub>, the conduction region is perfectly insulated |
| B. | At r = r <sub>1</sub>, the conduction region is partially insulated |
| C. | Heat flow is infinity |
| D. | Heat flow is negative |
| Answer» B. At r = r <sub>1</sub>, the conduction region is partially insulated | |
| 10. |
Consider the above problem, find the temperature at 5 cm radius |
| A. | 348.9 degree Celsius |
| B. | 358.9 degree Celsius |
| C. | 368.9 degree Celsius |
| D. | 378.9 degree Celsius |
| Answer» E. | |
| 11. |
A solid sphere of 8 cm radius has a uniform heat generation 0f 4000000 W/m3. The outside surface is exposed to a fluid at 150 degree Celsius with convective heat transfer coefficient of 750 W/m2 K. If thermal conductivity of the solid material is 30 W/m K, determine maximum temperature |
| A. | 444.45 degree Celsius |
| B. | 434.45 degree Celsius |
| C. | 424.45 degree Celsius |
| D. | 414.45 degree Celsius |
| Answer» C. 424.45 degree Celsius | |
| 12. |
The general solution for temperature distribution in case of solid sphere is |
| A. | t = t <sub>W</sub> + q <sub>g</sub> (R <sub>2</sub> – r <sub>2</sub>)/4 k |
| B. | t = t <sub>W</sub> + q <sub>g</sub> (R <sub>2</sub> – r <sub>2</sub>)/8 k |
| C. | t = t <sub>W</sub> + q <sub>g</sub> (R <sub>2</sub> – r <sub>2</sub>)/6 k |
| D. | t = t <sub>W</sub> + q <sub>g</sub> (R <sub>2</sub> – r <sub>2</sub>)/2 k |
| Answer» D. t = t <sub>W</sub> + q <sub>g</sub> (R <sub>2</sub> ‚Äö√Ñ√∂‚àö√ë‚àö¬® r <sub>2</sub>)/2 k | |
| 13. |
What is the heat flow for steady state conduction for sphere? |
| A. | 4 Q <sub>R </sub>+ Q <sub>G </sub>= Q <sub>R + d R</sub> |
| B. | 3 Q <sub>R </sub>+ Q <sub>G </sub>= Q <sub>R + d R</sub> |
| C. | 2 Q <sub>R </sub>+ Q <sub>G </sub>= Q <sub>R + d R</sub> |
| D. | Q <sub>R </sub>+ Q <sub>G </sub>= Q <sub>R + d R</sub> |
| Answer» E. | |
| 14. |
Consider the above problem, calculate the heat flow from the outer surface of the orange |
| A. | 4.82 k J/hr |
| B. | 5.82 k J/hr |
| C. | 6.82 k J/hr |
| D. | 7.82 k J/hr |
| Answer» B. 5.82 k J/hr | |
| 15. |
An 8 cm diameter orange, approximately spherical in shape, undergoes ripening process and generates 18000 k J/m3 hr of energy. If external surface of the orange is at 6.5 degree Celsius, find out the temperature at the center of the orange. Take thermal conductivity = 0.8 k J/ m hr degree for the orange material |
| A. | 13.5 degree Celsius |
| B. | 12.5 degree Celsius |
| C. | 11.5 degree Celsius |
| D. | 10.5 degree Celsius |
| Answer» C. 11.5 degree Celsius | |
| 16. |
Consider heat conduction through a solid sphere of radius R. There are certain assumptions |
| A. | Unsteady state conditions |
| B. | One-dimensional radial conduction |
| C. | Constant thermal conductivity |
| Answer» C. Constant thermal conductivity | |