Chemical Engineering - Chemical Engineering Basics
Exercise :: Chemical Engineering Basics - Section 18
41.
In 18-4-1 high speed steel, 18, 4 & 1 respectively denote the percentage of
A. chromium, tungsten & vanadium. B. tungsten, chromium & vanadium. C. tungsten, vanadium & chromium. D. tungsten, chromium & molybdenum.
Answer: Option B
Explanation:
42.
Role of a "collector" in froth floatation is to
A. form a water repelling film on the mineral surface. B. create and stabilise the froth. C. act as a surface. D. collect the minerals according to their specific gravity.
Answer: Option A
Explanation:
43.
For the running of power generating turbines, the steam used should be
A. wet B. superheated C. at ordinary pressure D. none of these
Answer: Option B
Explanation:
44.
Creep consideration is the most important in case of the
A. blades of gas turbines. B. steam engine flywheel. C. cast iron pipes. D. cycle chains.
Answer: Option A
Explanation:
45.
The diffusion co-efficient of Ni in Cu at 1000 K is 1.93 x 10-16 m2 . S-1 and it is 1.94 x 10-14 m2 S-1 at 1200 K. The activation energy (in k. J.mole-1 ) for the diffusion of Ni in Cu is
Answer: Option C
Explanation:
