MCQOPTIONS
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MCQOPTIONS
This section includes 13 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 wavelength band for solar radiation? |
| A. | 1 * 10 -1 to 3 micron meter |
| B. | 1 * 10 -1 to 2 micron meter |
| C. | 1 * 10 -1 to 1 micron meter |
| D. | 1 * 10 -1 to 10 micron meter |
| Answer» B. 1 * 10 -1 to 2 micron meter | |
| 2. |
A black body of total area 0.045 m2 is completely enclosed in a space bounded by 5 cm thick walls. The walls have a surface area 0.5 m 2 and thermal conductivity 1.07 W/ m K. If the inner surface of the enveloping wall is to be maintained at 215 degree Celsius and the outer wall surface at 30 degree Celsius, calculate the temperature of the black body |
| A. | 547.3 K |
| B. | 287.4 K |
| C. | 955.9 K |
| D. | 222.2 K |
| Answer» D. 222.2 K | |
| 3. |
What is the wavelength band for Ultraviolet rays? |
| A. | 1 * 10 -6 to 3.9 * 10 -1 micron meter |
| B. | 1 * 10 -4 to 3.9 * 10 -1 micron meter |
| C. | 2 * 10 -3 to 3.9 * 10 -1 micron meter |
| D. | 1 * 10 -2 to 3.9 * 10 -1 micron meter |
| Answer» E. | |
| 4. |
Measurements were made of the monochromatic absorptivity and monochromatic hemispherical irradiation incident on an opaque surface, and the variation of these parameters with wavelength may be approximated by the result shown below. Determine the total hemispherical absorptivity |
| A. | 0.557 |
| B. | 0.667 |
| C. | 0.777 |
| D. | 0.887 |
| Answer» C. 0.777 | |
| 5. |
If the emitted radiant energy is to be doubled, to what temperature surface of black body needs to be raised? Take radiant flux density as 11631.7 W/m 2. |
| A. | 894.4 K |
| B. | 200.4 K |
| C. | 800.3 K |
| D. | 600.4 K |
| Answer» E. | |
| 6. |
WHAT_IS_THE_WAVELENGTH_BAND_FOR_ULTRAVIOLET_RAYS??$ |
| A. | 1 * 10 <sup>-6</sup> to 3.9 * 10 <sup>-1</sup> micron meter |
| B. | 1 * 10 <sup>-4</sup> to 3.9 * 10 <sup>-1</sup> micron meter |
| C. | 2 * 10 <sup>-3</sup> to 3.9 * 10 <sup>-1</sup> micron meter |
| D. | 1 * 10 <sup>-2</sup> to 3.9 * 10 <sup>-1</sup> micron meter |
| Answer» D. 1 * 10 <sup>-2</sup> to 3.9 * 10 <sup>-1</sup> micron meter | |
| 7. |
A_black_body_of_total_area_0.045_m2_is_completely_enclosed_in_a_space_bounded_by_5_cm_thick_walls._The_walls_have_a_surface_area_0.5_m_2_and_thermal_conductivity_1.07_W/_m_K._If_the_inner_surface_of_the_enveloping_wall_is_to_be_maintained_at_215_degree_Celsius_and_the_outer_wall_surface_at_30_degree_Celsius,_calculate_the_temperature_of_the_black_body$ |
| A. | 547.3 K |
| B. | 287.4 K |
| C. | 955.9 K |
| D. | 222.2 K |
| Answer» B. 287.4 K | |
| 8. |
The value of radiation coefficient or the Stefan-Boltzmann constant is |
| A. | 5.67 * 10<sup> -8</sup> W/m<sup>2</sup> K<sup>4</sup> |
| B. | 5.67 * 10<sup> -7</sup> W/m<sup>2</sup> K<sup>4</sup> |
| C. | 5.67 * 10<sup> -6</sup> W/m<sup>2</sup> K<sup>4</sup> |
| D. | 5.67 * 10<sup> -5</sup> W/m<sup>2</sup> K<sup>4</sup> |
| Answer» C. 5.67 * 10<sup> -6</sup> W/m<sup>2</sup> K<sup>4</sup> | |
| 9. |
A furnace having inside temperature of 2250 has a glass circular viewing of 6 cm diameter. If the transmissivity of glass is 0.08, make calculations for the heat loss from the glass window due to radiation |
| A. | 234.54 W |
| B. | 652.32 W |
| C. | 328.53 W |
| D. | 762.32 W |
| Answer» B. 652.32 W | |
| 10. |
If the emitted radiant energy is to be doubled, to what temperature surface of black body needs to be raised? Take radiant flux density as 11631.7 W/m 2. |
| A. | 894.4 K |
| B. | 200.4 K |
| C. | 800.3 K |
| D. | 600.4 K |
| Answer» D. 600.4 K | |
| 11. |
Calculate the radiant flux density from a black surface at 400 degree Celsius? |
| A. | 1631.7 W/m<sup>2</sup> |
| B. | 31.7 W/m<sup>2</sup> |
| C. | 631.7 W/m<sup>2</sup> |
| D. | 11631.7 W/m<sup>2</sup> |
| Answer» E. | |
| 12. |
According to Stefan-Boltzmann law of thermal radiation |
| A. | q = α A T |
| B. | q = α A T<sup>4</sup> |
| C. | q = α A T<sup>3</sup> |
| D. | q = α A T<sup>5</sup> |
| Answer» C. q = ‚âà√≠¬¨¬± A T<sup>3</sup> | |
| 13. |
The Stefan-Boltzmann constant has units of |
| A. | kcal/m<sup>2</sup> hr K<sup>4</sup> |
| B. | kcal/m hr K<sup>4</sup> |
| C. | kcal/hr K<sup>4</sup> |
| D. | kcal/m<sup>2</sup> K<sup>4</sup> |
| Answer» B. kcal/m hr K<sup>4</sup> | |