Chemical Engineering - Chemical Engineering Basics
Exercise :: Chemical Engineering Basics - Section 11
| 31. |
A thermally thin body is the one for which |
| A. |
Biot number is less than 0.1. | | B. |
Gallileo number is less than 0.1. | | C. |
Fourier number is less than 0.1. | | D. |
Fourier number is greater than 0.1. |
Answer: Option A
Explanation:
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| 32. |
Air refrigeration cycle is used in the air crafts, because of |
| A. |
low temperature encountered at high altitude. | | B. |
its high heat transfer rate. | | C. |
its low unit weight per ton of refrigeration. | | D. |
its higher co-efficient of performance (COP). |
Answer: Option C
Explanation:
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| 33. |
Failure of a material is attributed to __________ if it fails below its yield point. |
| A. |
impact loading | | B. |
fatigue | | C. |
creep | | D. |
straining |
Answer: Option B
Explanation:
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| 34. |
Protection of ship hulls against sea water corrosion is done by coating with zinc because of the fact that zinc compared to iron is |
| A. |
reduced preferentially. | | B. |
cheaper. | | C. |
oxidised preferentially. | | D. |
lighter. |
Answer: Option C
Explanation:
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| 35. |
Which of the following pairs regarding the effect of alloying elements in steels are not matched correctly ? |
| A. |
Cobalt: It contributes to rerl hardness by hardening ferrite. | | B. |
Molybdenum: It forms abrasion resisting particles. | | C. |
Phosphorous: It improves machinability in free cutting steels. | | D. |
Silicon: It reduces oxidation resistance. |
Answer: Option A
Explanation:
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