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. |
Consider a beam of monochromatic radiation at wavelength λ that enters a layer of absorbing gas. As the beam passes through the gas layer, its intensity is given by |
| A. | d I λ X = – K λ I λ X d x |
| B. | d I λ X = – 2 K λ I λ X d x |
| C. | d I λ X = – 3 K λ I λ X d x |
| D. | d I λ X = – 4 K λ I λ X d x |
| Answer» B. d I λ X = – 2 K λ I λ X d x | |
| 2. |
Which one of the following is not extremely inert to thermal radiation? |
| A. | Orgon |
| B. | Oxygen |
| C. | Methane |
| D. | Nitrogen |
| Answer» D. Nitrogen | |
| 3. |
The monochromatic absorption coefficient depends upon(i) Temperature(ii) Time(iii) Pressure(iv) WavelengthIdentify the correct option |
| A. | i, ii and iv |
| B. | ii, iii and iv |
| C. | i and ii |
| D. | i, iii and iv |
| Answer» E. | |
| 4. |
Consider a beam of monochromatic radiation at wavelength λ that enters a layer of absorbing gas. As the beam passes through the gas layer, its intensity |
| A. | Decreases |
| B. | Increases |
| C. | Become twice |
| D. | Remains same |
| Answer» B. Increases | |
| 5. |
Consider an enclosure formed by three surfaces having the following values of shape factors, emissivities and temperaturesSurface 1 i.e. curved cylindrical has an emissivity 0.75 and temperature 800 KSurface 2 i.e. closing disc has an emissivity 0.8 and temperature 700 KSurface 3 i.e. closing disc has an emissivity 0.8 and temperature 700 KThe closing flat discs are 25 mm in diameter and they have interspacing distance equal to 100 mm. If the shape factor between these two identical discs is 0.05, calculate the net rate of radiant heat flow from the curve surface to each of the closing end surface |
| A. | 1.561 W |
| B. | 2.561 W |
| C. | 3.561 W |
| D. | 4.561 W |
| Answer» D. 4.561 W | |
| 6. |
WHICH_ONE_OF_THE_FOLLOWING_IS_NOT_EXTREMELY_INERT_TO_THERMAL_RADIATION??$ |
| A. | Orgon |
| B. | Oxygen |
| C. | Methane |
| D. | Nitrogen |
| Answer» D. Nitrogen | |
| 7. |
Consider_a_beam_of_monochromatic_radiation_at_wavelength_λ_that_enters_a_layer_of_absorbing_gas._As_the_beam_passes_through_the_gas_layer,_its_intensity_is_given_by$# |
| A. | d I <sub>λ X </sub>= – K <sub>λ </sub>I <sub>λ X</sub> d x |
| B. | d I <sub>λ X </sub>= – 2 K <sub>λ </sub>I <sub>λ X</sub> d x |
| C. | d I <sub>λ X </sub>= – 3 K <sub>λ </sub>I <sub>λ X</sub> d x |
| D. | d I <sub>λ X </sub>= – 4 K <sub>λ </sub>I <sub>λ X</sub> d x |
| Answer» B. d I <sub>‚âà√≠¬¨‚Ñ¢ X </sub>= ‚Äö√Ñ√∂‚àö√ë‚àö¬® 2 K <sub>‚âà√≠¬¨‚Ñ¢ </sub>I <sub>‚âà√≠¬¨‚Ñ¢ X</sub> d x | |
| 8. |
The monochromatic absorption coefficient depends upo? |
| A. | Temperature |
| B. | Time |
| C. | Pressure |
| D. | Wavelength |
| Answer» E. | |
| 9. |
When a gas or vapor is in the process of oxidation and combustion, it is called as |
| A. | Oxidation |
| B. | Flame |
| C. | Reduction |
| D. | Combustion |
| Answer» C. Reduction | |
| 10. |
Consider a beam of monochromatic radiation at wavelength λ that enters a layer of absorbing gas. As the beam passes through the gas layer, its intensity$ |
| A. | Decreases |
| B. | Increases |
| C. | Become twice |
| D. | Remains same |
| Answer» B. Increases | |
| 11. |
Some of the gases have low emissive power and absorptivity. They are considered practically diathermanous. Which of the following option is true? |
| A. | Ammonia |
| B. | Helium |
| C. | Carbon-dioxide |
| D. | Methane |
| Answer» C. Carbon-dioxide | |
| 12. |
Which layers participated in the process of thermal radiation through solids and liquids? |
| A. | 1 micron to 1 mm thick |
| B. | 2 micron to 2 mm thick |
| C. | 1 micron to 0.5 mm thick |
| D. | 2 micron to 4.57 mm thick |
| Answer» B. 2 micron to 2 mm thick | |
| 13. |
Which of the following is/are known as selective absorbers? |
| A. | Solids |
| B. | Liquids |
| C. | Gases and vapors |
| D. | Vapors |
| Answer» D. Vapors | |
| 14. |
Which of the following have a continuous spectrum? |
| A. | Solids |
| B. | Liquids |
| C. | Gases |
| D. | Solids and liquids |
| Answer» E. | |