Engineering :: Heat Transfer
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| 141. |
Thermal conductivity of wood least depends on |
| A. |
Moisture |
B. |
Density |
| C. |
Temperature |
D. |
Grain orientation |
| E. |
All of the above |
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Answer: Option D
Explanation:
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| 142. |
In air prelieater for boiler heat is least transferred by |
| A. |
Conduction |
B. |
Convection |
| C. |
Conduction and convection |
D. |
Radiation |
| E. |
Conduction, convection and radiation. |
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Answer: Option D
Explanation:
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| 143. |
Which method can be used for heating wood? |
| A. |
Flame heating |
B. |
Resistance heating |
| C. |
Dielectric heating |
D. |
Radiation heating |
| E. |
Any of the above |
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Answer: Option C
Explanation:
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| 144. |
The total solar radiation incident on a body is 1000 kcal/min. The body reflects 400 kcal/min. If the transmissivity of the surface will be |
Answer: Option D
Explanation:
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| 145. |
The phenomenon of boiling the milk in an open container when milk spills over the vessel is termed as |
| A. |
Film boiling |
B. |
Pool boiling |
| C. |
Nuclear boiling |
D. |
Sub-cooled boiling |
| E. |
Interface evaporation |
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Answer: Option A
Explanation:
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| 146. |
The value of the wavelength for maximum emissive power is given by |
| A. |
Planck's law |
B. |
D'Alembert's rule |
| C. |
Kirchhoff's law |
D. |
Stefan law |
| E. |
Wein's law |
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Answer: Option E
Explanation:
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| 147. |
Which type of heat exchanger an automobile radiator is? |
| A. |
Parallel flow type |
B. |
Counter flow type |
| C. |
Recuperator type |
D. |
Regenerator type |
| E. |
Cross flow type |
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Answer: Option E
Explanation:
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| 148. |
A hollow sphere with uniform interior temperature and a small hole behaves very nearly as a |
| A. |
Grey body |
B. |
White body |
| C. |
Opaque body |
D. |
Transparent body |
| E. |
Black body |
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Answer: Option E
Explanation:
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| 149. |
A body which transmits all the radiations falling on it is known as |
| A. |
Black body |
B. |
Grey body |
| C. |
Transparent body |
D. |
White body |
| E. |
None of the above |
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Answer: Option C
Explanation:
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| 150. |
A black body absorbs all radiations. As a result of absorption of these radiations |
| A. |
A black body shines |
B. |
The temperature of black body rises |
| C. |
Black body radiates energy to other bodies |
D. |
Black body becomes good conductor of heat |
Answer: Option B
Explanation:
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