MCQOPTIONS
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MCQOPTIONS
This section includes 15 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 the following statements regarding nucleate boiling(i) The temperature of the surface is greater than the saturation temperature of the liquid(ii) Bubbles are created by the expansion of entrapped gas oil vapor at small cavities in the surface(iii) The temperature is greater than that in film boiling(iv) The heat transfer from the surface to the liquid is greater than that in the film boilingWhich of these statements are correct? |
| A. | i and iii |
| B. | i, ii and iv |
| C. | ii, iii and iv |
| D. | i, ii and iii |
| Answer» C. ii, iii and iv | |
| 2. |
Leiden-frost expansion is related to |
| A. | Condensation of vapor on a cold surface |
| B. | Exchange of heat between two solids |
| C. | Evaporation of a solution |
| D. | Boiling of liquid on a hot surface |
| Answer» E. | |
| 3. |
Heat flux increases with temperature excess beyond the Leiden-frost point due to |
| A. | Radiation effect becomes predominant |
| B. | Occurrence of subcooled boiling |
| C. | Vapor space become large |
| D. | Promotion of nucleate boiling |
| Answer» B. Occurrence of subcooled boiling | |
| 4. |
The bubble diameter at the time of detachment from the surface can be worked out from the relation proposed by Fritz and is given by |
| A. | C d β [2 σ/g (p t – p v)]. |
| B. | C d β [2 σ/g (p t – p v)] 3/2 |
| C. | C d β [2 σ/g (p t – p v)] 1/2 |
| D. | C d β [2 σ/g (p t – p v)] 5/2 |
| Answer» D. C d β [2 σ/g (p t – p v)] 5/2 | |
| 5. |
Consider the following phenomena(i) Boiling(ii) Free convection in air(iii) Forced convection in air(iv) Conduction in airIdentify the correct sequence (heat transfer coefficient) |
| A. | iii – iv – i – ii |
| B. | iv – i – iii – ii |
| C. | iv – iii – ii – i |
| D. | iv – ii – iii – i |
| Answer» E. | |
| 6. |
The nucleate pool boiling is influenced by the following factors(1) Pressure(2) Liquid properties(3) MaterialIdentify the correct statements |
| A. | i, ii and iii |
| B. | ii only |
| C. | i and ii |
| D. | ii and iii |
| Answer» B. ii only | |
| 7. |
LEIDEN-FROST_EXPANSION_IS_RELATED_TO?$ |
| A. | Condensation of vapor on a cold surface |
| B. | Exchange of heat between two solids |
| C. | Evaporation of a solution |
| D. | Boiling of liquid on a hot surface |
| Answer» E. | |
| 8. |
Consider_the_following_statements_regarding_nucleate_boiling$ |
| A. | The temperature of the surface is greater than the saturation temperature of the liquid |
| B. | Bubbles are created by the expansion of entrapped gas oil vapor at small cavities in the surface |
| C. | The temperature is greater than that in film boiling |
| D. | The heat transfer from the surface to the liquid is greater than that in the film boiling |
| Answer» C. The temperature is greater than that in film boiling | |
| 9. |
Heat flux increases with temperature excess beyond the Leiden-frost point due t? |
| A. | Radiation effect becomes predominant |
| B. | Occurrence of subcooled boiling |
| C. | Vapor space become large |
| D. | Promotion of nucleate boiling |
| Answer» B. Occurrence of subcooled boiling | |
| 10. |
The excess temperature range 50 degree Celsius < d t < 200 degree Celsius is indicative of the region of |
| A. | Interface evaporation |
| B. | Nuclear boiling |
| C. | Partial film boiling |
| D. | Stable film boiling |
| Answer» D. Stable film boiling | |
| 11. |
With increase in excess temperature, the heat flux in boiling |
| A. | Increases continuously |
| B. | Decreases and then increases |
| C. | Decreases, then increases and again decreases |
| D. | Increases, then decreases and again increases |
| Answer» E. | |
| 12. |
In spite of large heat transfer coefficient in boiling liquids, fins are used advantageously when the entire surface is exposed to |
| A. | Film boiling |
| B. | Transition boiling |
| C. | Nucleate boiling |
| D. | All modes of boiling |
| Answer» E. | |
| 13. |
Consider the following phenomena |
| A. | Boiling |
| B. | Free convection in air |
| C. | Forced convection in air |
| D. | Conduction in air |
| Answer» E. | |
| 14. |
The nucleate pool boiling is influenced by the following factors |
| A. | Pressure |
| B. | Liquid properties |
| C. | Material |
| Answer» B. Liquid properties | |
| 15. |
The bubble diameter at the time of detachment from the surface can be worked out from the relation proposed by |
| A. | Stanton |
| B. | Fritz |
| C. | Fourier |
| D. | Nusselt |
| Answer» C. Fourier | |