MCQOPTIONS
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MCQOPTIONS
This section includes 9 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. |
Two long rods A and B of the same diameter have thermal conductivities k and 4k and have one of their end inserted into a furnace at 400 K. At 9.5 m away section from the furnace, the temperature of rod B is120 degree Celsius. So find out at what end from the furnace end, the same temperature would be reached in the rod A? |
| A. | 0.25 m |
| B. | 0.75 m |
| C. | 0.15 m |
| D. | 0.50 m |
| Answer» B. 0.75 m | |
| 2. |
Three fins of equal length and diameter but made of aluminum, brass and cast iron is heated to 200 degree Celsius at one end. If the fins dissipate heat to the surrounding air at 25 degree Celsius, the temperature at the free end will be least in |
| A. | Brass fin |
| B. | Cast iron fin |
| C. | Aluminum fin |
| D. | Each fin will have the same temperature |
| Answer» D. Each fin will have the same temperature | |
| 3. |
Effectiveness of fin is the ratio of the fin heat dissipation with fin to that of no fin . |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4. |
For a straight rectangular fin of thickness and width b, choose the correct option |
| A. | P/A<sub>C</sub> = 1/ |
| B. | P/A<sub>C</sub> = 2/ |
| C. | P/A<sub>C</sub> = 3/ |
| D. | P/A<sub>C</sub> = 4/ |
| Answer» C. P/A<sub>C</sub> = 3/ | |
| 5. |
For an infinitely long fin, the effectiveness of fin is given as |
| A. | (P k/h A<sub>C</sub>) |
| B. | (P k/h A<sub>C</sub>)<sup>3/2</sup> |
| C. | (P k/h A<sub>C</sub>)<sup>1/2</sup> |
| D. | (P k/h A<sub>C</sub>)<sup>2</sup> |
| Answer» D. (P k/h A<sub>C</sub>)<sup>2</sup> | |
| 6. |
For a fin of finite length with an insulated end, the fin efficiency is given as |
| A. | tan h (ml) |
| B. | tan (ml)/ml |
| C. | tan h (m)/ml |
| D. | tan h (ml)/ml |
| Answer» E. | |
| 7. |
For an infinitely long fin, the efficiency of fin is given by |
| A. | 1/ml |
| B. | 2/ml |
| C. | 3/ml |
| D. | 4/ml |
| Answer» B. 2/ml | |
| 8. |
A copper steel rod (k = 55 W/m degree) has been attached to a plane wall which is maintained at a temperature of 350 degree Celsius. The rod is 8 cm long and has the cross-section of an equilateral triangle with each side 5 mm. Determine the heat dissipation from the rod if it is exposed to a convection environment at 25 degree Celsius with unit surface conductance 100 W/m2 degree. Consider end surface loss to be negligible |
| A. | 10.26 W |
| B. | 9.26 W |
| C. | 8.26 W |
| D. | 7.26 W |
| Answer» C. 8.26 W | |
| 9. |
The utility of fin in dissipating a given quantity of heat is generally assessed on the basic of how many parameters? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |