Top 60 Unit Operations & Power Plant Instrumentation Objective Questions and Answers

 Top 60 Unit Operations & Power Plant Instrumentation Objective Questions and Answers

1. What is the removal of fine particle sand from dissolved solids called?

a) Filteration

b) sedimentation

c) disinfection

d) deoxidation

Answer: Filteration

2. In distillation, overhead product contains 

a) Only one component

b) two components

c) any number of component

d) saturated liquid

Answer: any number of component

3. Separation of two or more components of a liquid solution can not be achieved by

a) Fractional Crystallisation

b) Liquid Extraction

c) Absorption

d) Evaporation

Answer: Absorption

4. Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases.

a) Chemical properties

b) Physical properties

c) Degree of turbulence

d) Interfacial area

Answer: Chemical properties

5. The main function of centrifugal pumps are to ________ 

a) Transfer speed

b) Transfer pressure

c) Transfer temperature

d) Transfer energy

Answer: Transfer energy

6. Drying operation under vacuum is carried out to 

a) Dry those materials which have very high unbound mositure content.

b) Reduce drying temperature.

c) Increase drying temperature.

d) Dry materials having high bound moisture content.

Answer: Reduce drying temperature.

7. Overall efficiency of the distillation column is

a) The ratio of number of ideal plates to actual plates.

b) The ratio of number of actual plates to ideal plates

c) Same as the Murphree efficiency.

d) Always more than the point efficiency.

Answer: The ratio of number of ideal plates to actual plates.

8. The process of heat transfer from one particle of the body to another without actual motion of the particle is called

a) Radiation

b) Conduction

c) Convection

d) none of the bove

Answer: Convection

9. Direct dryers are ___________ 

a) Batch Dryer

b) Continuous dryer

c) semi batch dryer

d) none of the above

Answer: Batch Dryer

10. In heat exchangers, the value of logarithmic mean temperature difference should be 

a) Maximum possible

b) Minimum possible

c) constant

d) zero

Answer: Maximum possible

11. Simple distillation is a___________ process.

a) continuous

b) batch

c) adiabatic

d) none of the mention above

Answer: batch

12. Thermal conductivity of water _________ with rise in temperature.

a) Remain same

b) Decreases

c) increases

d) may increase or decrease

Answer: may increase or decrease

13. Which of the following is a nonrenewable energy resource?

a) Solar

b) methane

c) hydroelectric

d) coal

Answer: coal

14. Nuclear energy is derived by ___________.

a) Combustion of atoms of U 235

b) Fission of atoms of U 235

c) Fusion of atoms of U 235

d) The breaking of U 235 bonds

Answer: Fission of atoms of U 235

15. Which among the following have a large amount of installed grid interactive renewable power capacity in India?

a) solar power

b) wind power

c) small hydro power

d) biomass

Answer: wind power

16. Wood is a renewable resource.

a) True

b) False

Answer: true 

17. Which of the following is a disadvantage of renewable energy?

a) High pollution

b) Available only in few places

c) High running cost

d) Unreliable supply

Answer: Unreliable supply

18. The world’s first 100% solar powered airport located at ____________ 

a) Cochin, Kerala

b) Bengaluru, Karnataka

c)  Chennai, Tamil Nadu

d) Mumbai, Maharashtra

Answer: Cochin, Kerala

19. Which of the following nonrenewable energy is not classified under a fossil fuel?

a) petrolium

b) nuclear

c) oil

d) natural gas

Answer: nuclear

20. A Solar cell is an electrical device that converts the energy of light directly into electricity by the ____________

a) Photovoltaic effect

b) Chemical effect

c) Atmospheric effect

d) physical effect

Answer: Photovoltaic effect

21. An economizer in a boiler 

a)Increases steam pressure

b) Increases steam flow

C)decreases fuel consumption

d)decreases steam flow

Answer: decreases fuel consumption

22. Size of boiler tubes is specified by

a) Mean diameter and thickness

b) Inside diameter and thickness

c) Outside diameter and thickness

d) Outside diameter and inside diameter

Answer: Outside diameter and thickness

23. The water tubes in a simple vertical boiler are 

a) horiontal

b) vertical

c) inclined

d) all of the above

Answer: inclined

24. In thermal power plants, the dust of flue gases is trapped by 

a) precipitator

b) economier

c) air preheater

d) superheater

Answer: precipitator

25. The path of flue gases in Thermal power plant is 

a) Boiler – Economizer

b) boiler -air preheater

c) Boiler – preheater

d) Boiler – superheater

Answer: Boiler – superheater

26. The following is not a component of Thermal power plant 

a) Condenser

b) fuel tank

c) cooling tower

d) turbine

Answer: fuel tank

27. Francis,kaplan and propeller turbines fall under the category of 

a) impulse turbine

b) axial flow

c) reaction turbine

d) impulse reaction combine

Answer: reaction turbine

28. Which energy generated in a turbine is used to run electric power generator linked to the turbine shaft? 

a) mechanical energy

b) potential energy

c) kinetic energy

d) elastic energy

Answer: mechanical energy

29. Which kind of turbines changes the pressure of the water entered through it?

a) Impulse turbine

b) reaction turbine

c) relative turbine

d) kinetic turbine

Answer: reaction turbine

30. The head available at inlet of turbine

a) Net positive suction head

b) gross head

c) net head

d) manometric head

Answer: net head

31. A mixture of theoretical air and fuel for complete combustion of fuel is called 

a) Rich mixture

b) Lean mixture

c) Air-fuel mixture

d) Stoichiometric mixture

Answer: Stoichiometric mixture

32. Mixture strength is defined as the ratio of

a) Stoichiometric Air-fuel ratio / Actual Air-fuel ratio

b) Stoichiometric Air-fuel ratio / Theoretical Air-fuel ratio

c) Actual Air-fuel ratio / Stoichiometric Air-fuel ratio

d) Theoretical Air-fuel ratio / Stoichiometric Air-fuel ratio

Answer: Stoichiometric Air-fuel ratio / Actual Air-fuel ratio

33. In power plants cooling towers are used to 

a) Cool exhaust steam

b) Cool repeated steam

c) Cool feed water

d) Cool condenser outlet

Answer: Cool condenser outlet

34. Which of the following equipment is installed to minimize pollution of surroundings ? 

a) Water treatment plant

b) De-super heaters

c) Cooling towers

d) Electrostatic precipitator

Answer: Electrostatic precipitator*

35. _____ are used in electrostatic precipitators. 

a) Catalysts

b) Absorbers

c) Electrodes

d) chemicals

Answer: Electrodes

36. Which of the following is an air pollutant? 

a) Nitrogen

b) Carbon dioxide

c) Carbon monoxide

d) oxygen

Answer: Carbon monoxide

37. Which of the following air pollution control devices is suitable for the removing the finest dust from the air? 

a) cyclone separator

b) Electrostatic Precipitator

c) Fabric filter

d) weight scrubber

Answer: Electrostatic Precipitator

38. Which of the following is not a requirement for site selection of hydroelectric power plant?

a) Availability of water

b) Large catchment area

c) Rocky land

d) Sedimentation

Answer: Sedimentation

39. The overall efficiency of thermal power plant is equal to 

a) Ranklin cycle efficiency

b) Carnot cycle efficiency

c) Boiler efficiency x turbine efficiency x generator efficiency

d) Regenarative cycle efficiency

Answer: Regenarative cycle efficiency

40. The best capable alternative source which can meet the future energy demand is __________ 

a) Thermal Power Plant

b) Nuclear Power Plant

c) Geothermal Power Plant

d) Hydraulic power plant

Answer: Nuclear Power Plant

41. In power plant an electrostatic precipitators is installed 

a) Forced draft fan and furnace

b) Furnace and chimney

c) Primary air and secondary air

d) induced draft fan and forced draft fan

Answer: Furnace and chimney

42. The artificial draught normally is designed to produce 

a) Concrete and bricks

b) more draught

c) Graphite and concrete

d) fan or steam jet

Answer: more draught

43. Nuclear power plants approximately consume how many gallons of water per MWh:

a) 10 – 250

b) 250 – 670

c) 670 – 2190

d) 3000

Answer: 250 – 670

44. Nuclear fuel in reactor lasts for ____________ 

a) more than 5 months

b) few weeks

c) few days

d) more than 5 years

Answer: more than 5 years

45. The height of chimney in a steam power plant is governed by_____

a) Flue gases quantity

b) The draught to be produced

c) Control of pollution

d) Corner of power plant

Answer: Control of pollution

46. The major heat loss in a steam power station occurs in _______

a) Heat chember

b) Penstock

c) Spillways

d) Condenser

Answer: Condenser

47. In thermal power plant, turbine is placed 

a) before boiler

b) in between boiler and generator

c) after generator

d) Hydro electric power plant

Answer: in between boiler and generator

48. In thermal power plants, the dust of flue gases is trapped by

a) Precipitator

b) Economizer

c) Superheater

d) Air preheater

Answer: Precipitator

49. The following is the correct order of energy conversion in thermal power plants 

a) Chemical energy – Mechanical energy – Electrical energy

b) Mechanical energy – Chemical energy – Electrical energy

c) Wind energy – Mechanical energy – Electrical energy

d) Heat energy – Electrical energy – Mechanical energy

Answer: Chemical energy – Mechanical energy – Electrical energy

50. A random variable that assumes a finite or a countably infinite number of values is called ___________ 

a) X-rays

b) Infrared rays

c) Neutrons and gamma rays

d) Electrons

Answer: Neutrons and gamma rays*

51. The most commonly used moderator in nuclear plants is 

a) Heavy Water

b) Concrete and bricks

c) Graphite and concrete

d) Graphite

Answer: Graphite

52. What type of flow can be taken for granted in a pipe of a uniform cross-section?
a) steady
b) unsteady
c) uniform
d) non-uniform
Answer: uniform
53. “The velocity of entrance and exit through a nozzle remains the same.” Is this ever possible?
a) only if the flow is compressible
b) only if the flow is laminar
c) only if the flow is rotational
d) never possible
Answer: only if the flow is compressible
54. Can the flow inside a nozzle be steady and uniform?
a) yes
b) never
c) it can be steady but never uniform
d) it can be uniform but never steady
Answer: it can be steady but never uniform
55. What is unit for flow rate for gases?
a) m3/s
b) litres/s
c) cm3/s
d) kgf/s
Answer: kgf/s
56. Three flows named as 1,2 and 3 are observed. The Reynold’s number for the three are 100, 1000 and 10000. Which of the flows will be laminar?
a) only 1
b) only 1 and 2
c) 1, 2 and 3
d) only 3
Answer: only 1 and 2
57. Which of the following is true?
a) Flow is laminar inside the boundary layer and turbulent outside
b) Flow is turbulent inside the boundary layer and laminar outside
c) Flow is laminar both inside and outside of the boundary layer
d) Flow is turbulent both inside and outside of the boundary layer
Answer: Flow is laminar inside the boundary layer and turbulent outside
58. Which method is most commonly used in fluid mechanics for analysis?
a) Langragian method
b) Eulerian Method
c) Control volume analysis
d) None of the mentioned
Answer: Eulerian Method
59. In which method of fluid flow analysis do we describe the motion parameters at a point?
a) Langragian method
b) Eulerian Method
c) Control volume analysis
d) None of the mentioned
Answer: Eulerian Method
60. When the flow particles flow in zigzag manner and rotate about their own axis it is what type of flow?
a) Turbulent flow
b) Irrotational flow
c) Rotational flow
d) None of the mentioned
Answer: None of the mentioned

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