Power Plant Engineering Multiple Choice Questions on “Kinetic and Diffusion Control – I”.
1. Which of these is the outer most coating in the burning of a coke particle?
a) Oxygen
b) Carbon monoxide
c) Carbon dioxide
d) Ash Layer
Answer: a
Clarification: Oxygen, being a supporter of combustion helps in combustion of coke particle and so forms a layer on the periphery of the coke particle.
2. Which law deals with the rate of diffusion of Oxygen per unit surface area of the particle?
a) Kirchhoff’s Law
b) Plank’s Law
c) Fourier’s Law
d) Fick’s Law
Answer: d
Clarification: Fick’s Law deals with the rate of diffusion of Oxygen per unit surface area of the particle.
3. If d is the diffusion coefficient and t is the boundary layer thickness. Then the mass transfer coefficient k is given by?
a) k = d x t
b) k = d / t
c) k = d + t
d) k = d – t
Answer: b
Clarification: If d is the diffusion coefficient and t is the boundary layer thickness. Then the mass transfer coefficient k is given by,
k = d / t.
4. Gobar gas is produced by the __________ of ‘gobar’ (cow dung).
a) Fermentation
b) Condensation
c) Combustion
d) Distillation
Answer: a
Clarification: Fermentation is the process which converts cow’s dung into ‘Gobar Gas’.
5. Coking time in beehive coke oven is about __________
a) one week
b) 12 hours
c) 2-3 days
d) 2 weeks
Answer: c
Clarification: The total time of coking in a beehive oven is about 2-3 days.
6. __________ present in coal is not determined in its ultimate analysis.
a) Fixed Carbon
b) Total Carbon
c) Nitrogen
d) Hydrogen
Answer: a
Clarification: Fixed Carbon present in coal is not determined in its ultimate analysis. It is determined by Proximate analysis of Coal.
7. The maximum adiabatic flame temperature is attained when the fuel is burnt with __________
a) theoretically required amount of air
b) less than theoretically required amount of air
c) more than theoretically required amount of air
d) theoretically required amount of oxygen
Answer: d
Clarification: The maximum adiabatic flame temperature is attained when the fuel is burnt with theoretically required amount of Oxygen.
8. Height of coke oven is limited (say maximum up to 7 metres) mainly by the __________
a) problem of uniform heating along its height.
b) structural strength of silica bricks
c) problem in door cleaning
d) buckling of ram of pusher car at the time of coke pushing
Answer: a
Clarification: Height of coke oven is limited (say maximum up to 7 metres) mainly by the problem of Uniform heating as the heat is distributed along the height.
9. Which of the following has the highest calorific value?
a) Sub-bituminous
b) Anthracite
c) Lignite
d) Peat
Answer: b
Clarification: Among the given varieties of coal, the highest calorific value is possessed by the one which has the maximum carbon content. Here, Anthracite has the maximum Calorific Value.