MCQOPTIONS
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MCQOPTIONS
This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering Physics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What relation between emissivity, e, and Absorptive Power, a, is given by Kirchhoff s law? |
| A. | e < a |
| B. | e > a |
| C. | e = a |
| D. | no specific relation |
| Answer» D. no specific relation | |
| 2. |
For an object other than a black body, it s emissivity, e is _______________ |
| A. | 1 |
| B. | 0 < e < 1 |
| C. | e > 1 |
| D. | e = 0 |
| Answer» C. e > 1 | |
| 3. |
The unit of absorptive power is _______________ |
| A. | T |
| B. | Ts<sup>-1</sup> |
| C. | Ts |
| D. | No unit |
| Answer» E. | |
| 4. |
Electromagnetic wave theory of light could not explain Black Body radiations. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 5. |
A black body is defined as a perfect absorber of radiations. It may or may not be a perfect emitter of radiations. |
| A. | True |
| B. | False |
| Answer» C. | |
| 6. |
An iron rod is heated. The colors at different temperatures are noted. Which of the following colors shows that the iron rod is at the lowest temperature? |
| A. | Red |
| B. | Orange |
| C. | White |
| D. | Blue |
| Answer» B. Orange | |
| 7. |
The radiations emitted by hot bodies are called as ________________ |
| A. | X-rays |
| B. | Black-body radiation |
| C. | Gamma radiations |
| D. | Visible light |
| Answer» C. Gamma radiations | |
| 8. |
As the wavelength of the radiation decreases, the intensity of the black body radiations ____________ |
| A. | Increases |
| B. | Decreases |
| C. | First increases then decrease |
| D. | First decreases then increase |
| Answer» D. First decreases then increase | |