Chemical Engineering - Chemical Engineering Basics
Exercise :: Chemical Engineering Basics - Section 18
21.
Which of the following metals can be extracted from its ore by both pyrometallur-gical as well as hydrometallurgical methods ?
A. Copper B. Zinc C. both 'a' & 'b' D. neither 'a' nor 'b'
Answer: Option C
Explanation:
22.
If a heat transfer surface is pock-marked with a number of cavities, then as compared to a smooth surface the heat transfer by __________ will not increase.
A. convection B. nucleate boiling C. radiation D. conduction
Answer: Option A
Explanation:
23.
Piezoelectric is a material
A. whose properties is midway between the constituent materials. B. which gets polarised, when stressed. C. in which magnetising force reduces when current flowing through it is in-cresed. D. which changes dimensions due to applied field.
Answer: Option B
Explanation:
24.
Oxygen content below __________ percent in air contaminated with nitrogen does not support combustion and is unsafe for humane exposure.
Answer: Option B
Explanation:
25.
Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs.
A. enthalpy B. relative humidity C. wet bulb temperature D. dew point temperature
Answer: Option D
Explanation:
