MCQOPTIONS
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MCQOPTIONS
This section includes 14 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. |
What is the value of characteristics length for cube? |
| A. | L/3 |
| B. | L/4 |
| C. | L/5 |
| D. | L/6 |
| Answer» E. | |
| 2. |
What is the value of characteristics length for sphere? |
| A. | R/2 |
| B. | R/3 |
| C. | R/4 |
| D. | R/5 |
| Answer» C. R/4 | |
| 3. |
During heat treatment, cylindrical pieces of 25 mm diameter, 30 mm height and at 30 degree Celsius are placed in a furnace at 750 degree Celsius with convective coefficient 80 W/m2 degree. Find the value of biot number if thermal conductivity is 40 W/m degree |
| A. | 0.0082 |
| B. | 0.0072 |
| C. | 0.0062 |
| D. | 0.0052 |
| Answer» B. 0.0072 | |
| 4. |
Which is true regarding lumped system analysis?(i) Conductive resistance = 0(ii) Convective resistance = 0(iii) Thermal conductivity = 0(iv) Thermal conductivity = infinityIdentify the correct statements |
| A. | i and ii |
| B. | i, ii and iv |
| C. | i and iv |
| D. | ii and iv |
| Answer» D. ii and iv | |
| 5. |
Glass spheres of 2 mm radius and at 500 degree Celsius are to be cooled by exposing them to an air stream at 25 degree Celsius. Find the minimum time required for cooling to a temperature of 60 degree Celsius. Assume the following property valuesDensity = 2250 kg/m3Specific heat = 850 J/kg KConductivity = 1.5 W/m K |
| A. | 13.78 seconds |
| B. | 14.78 seconds |
| C. | 15.78 seconds |
| D. | 16.78 seconds |
| Answer» C. 15.78 seconds | |
| 6. |
WHAT_IS_THE_VALUE_OF_CHARACTERISTICS_LENGTH_FOR_SPHERE??$ |
| A. | R/2 |
| B. | R/3 |
| C. | R/4 |
| D. | R/5 |
| Answer» C. R/4 | |
| 7. |
What_is_the_value_of_characteristics_length_for_cube?$ |
| A. | L/3 |
| B. | L/4 |
| C. | L/5 |
| D. | L/6 |
| Answer» E. | |
| 8. |
During heat treatment, cylindrical pieces of 25 mm diameter, 30 mm height and at 30 degree Celsius are placed in a furnace at 750 degree Celsius with convective coefficient 80 W/m2 degree. Find the value of biot number if thermal conductivity is 40 W/m degre? |
| A. | 0.0082 |
| B. | 0.0072 |
| C. | 0.0062 |
| D. | 0.0052 |
| Answer» B. 0.0072 | |
| 9. |
What is the value of characteristics length for cylinder? |
| A. | R/5 |
| B. | R/4 |
| C. | R/3 |
| D. | R/2 |
| Answer» E. | |
| 10. |
What is the criterion for the applicability of lump system analysis? |
| A. | Mean length |
| B. | Normal length |
| C. | Characteristics length |
| D. | Mass no |
| Answer» D. Mass no | |
| 11. |
Which of the following is an example of lump system analysis? |
| A. | Heating or cooling of fine thermocouple wire due to change in ambient temperature |
| B. | Heating of an ingot in an furnace |
| C. | Cooling of bars |
| D. | Cooling of metal billets in steel works |
| Answer» B. Heating of an ingot in an furnace | |
| 12. |
Which is true regarding lumped system analysis? |
| A. | Conductive resistance = 0 |
| B. | Convective resistance = 0 |
| C. | Thermal conductivity = 0 |
| D. | Thermal conductivity = infinity |
| Answer» D. Thermal conductivity = infinity | |
| 13. |
The temperature and rate of heat conduction are undoubtedly dependent on |
| A. | Time coordinates |
| B. | Space coordinates |
| C. | Mass coordinates |
| D. | Both time and space coordinates |
| Answer» E. | |
| 14. |
According to lumped system analysis, solid possesses thermal conductivity that is |
| A. | Infinitely large |
| B. | Infinitely small |
| C. | Moderate |
| D. | 50% small |
| Answer» B. Infinitely small | |