MCQOPTIONS
Saved Bookmarks
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. |
Which one is true for an opaque body? |
| A. | Transmissivity is zero |
| B. | Reflectivity is zero |
| C. | Absorptivity is zero |
| D. | Reflectivity is unity |
| Answer» B. Reflectivity is zero | |
| 2. |
The total radiant energy A impinging upon a body would be partially or totally absorbed, reflected from its surface or transmitted through it. Identify the correct statement |
| A. | B is the energy that is absorbed by the body |
| B. | B is the energy that is reflected by the body |
| C. | C is the energy that is absorbed by the body |
| D. | D is the energy that is transmitted by the body |
| Answer» C. C is the energy that is absorbed by the body | |
| 3. |
Radiant energy with an intensity of 800 W/m2 strikes a flat plate normally. The absorptivity is thrice the reflectivity and twice the transmissivity. Determine the rate of reflection |
| A. | 518.20 W/m2 |
| B. | 418.20 W/m2 |
| C. | 318.20 W/m2 |
| D. | 218.20 W/m2 |
| Answer» E. | |
| 4. |
The value of reflectivity depends upon(i) Body temperature(ii) Wavelength of reflected radiation(iii) Nature of surface of bodyIdentify the correct statement |
| A. | i and ii |
| B. | ii and iii |
| C. | ii only |
| D. | i and iii |
| Answer» E. | |
| 5. |
A thin metal plate of 4 cm diameter is suspended in atmospheric air whose temperature is 290 K. This plate attains a temperature of 295 K when one of its face receives radiant energy from a heat source at the rate of 2 W. If heat transfer coefficient on both surfaces of the plate is stated to be 87.5 W/m 2 K, workout the energy lost by reflection |
| A. | 0.8 W |
| B. | 0.3 W |
| C. | 0.9 W |
| D. | 0.10 W |
| Answer» D. 0.10 W | |
| 6. |
Of the radiant energy 350W/m2 incident upon a surface 250W/m2 is absorbed, 60W/m2 is reflected and the remainder is transmitted through the surface. Workout the value for reflectivity for the surface material |
| A. | 0.181 |
| B. | 0.171 |
| C. | 0.161 |
| D. | 0.151 |
| Answer» C. 0.161 | |
| 7. |
Which one is true for an opaque body?$ |
| A. | Transmissivity is zero |
| B. | Reflectivity is zero |
| C. | Absorptivity is zero |
| D. | Reflectivity is unity |
| Answer» B. Reflectivity is zero | |
| 8. |
Radiant energy with an intensity of 800 W/m2 strikes a flat plate normally. The absorptivity is thrice the reflectivity and twice the transmissivity. Determine the rate of reflectio? |
| A. | 518.20 W/m<sup>2</sup> |
| B. | 418.20 W/m<sup>2</sup> |
| C. | 318.20 W/m<sup>2</sup> |
| D. | 218.20 W/m<sup>2</sup> |
| Answer» E. | |
| 9. |
Thin glass plate is an example of |
| A. | Transparent body |
| B. | Opaque body |
| C. | Black body |
| D. | White body |
| Answer» B. Opaque body | |
| 10. |
Which one is true regarding gases? |
| A. | Reflectivity is unity |
| B. | Absorptivity is zero |
| C. | Reflectivity is zero |
| D. | Transmissivity is zero |
| Answer» D. Transmissivity is zero | |
| 11. |
When a surface absorbs a certain fixed percentage of striking radiation the surface is called |
| A. | Grey body |
| B. | Black body |
| C. | White body |
| D. | Opaque body |
| Answer» B. Black body | |
| 12. |
A thin metal plate of 4 cm diameter is suspended in atmospheric air whose temperature is 290 K. This plate attains a temperature of 295 K when one of its face receives radiant energy from a heat source at the rate of 2 W. If heat transfer coefficient on both surfaces of the plate is stated to be 87.5 W/m 2 K, workout the energy lost by reflection |
| A. | 0.8 W |
| B. | 0.3 W |
| C. | 0.9 W |
| D. | 0.10 W |
| Answer» D. 0.10 W | |
| 13. |
Of the radiant energy 350W/m2 incident upon a surface 250W/m2 is absorbed, 60W/m2 is reflected and the remainder is transmitted through the surface. Workout the value for reflectivity for the surface material |
| A. | 0.181 |
| B. | 0.171 |
| C. | 0.161 |
| D. | 0.151 |
| Answer» C. 0.161 | |
| 14. |
Reflectivity is defined as |
| A. | Fraction of total energy transmitted by the body |
| B. | Fraction of energy reflected by the body |
| C. | Fraction of total energy absorbed by the body |
| D. | Fraction of total energy absorbed and radiated by the body |
| Answer» C. Fraction of total energy absorbed by the body | |