Chemical Engineering - Chemical Engineering Basics

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:

No answer description available for this question. Let us discuss.

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:

No answer description available for this question. Let us discuss.

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:

No answer description available for this question. Let us discuss.

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:

No answer description available for this question. Let us discuss.

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:

No answer description available for this question. Let us discuss.