Instrumentation and Control for Power Plants

Instrumentation and Control for Power Plants

1.  Feed water from the hot well is supplied to steam generator by using the _________ 
a) Sewers
b) Cistern
c) Water trough
d) Feed pump
Answer: Feed pump
2. Super heater tubes are made up of what type of material? 
a) Copper alloy
b) Carbon steel
c) Titanium alloy
d) Iron
Answer: Carbon steel
3. By what means the power in the steam power plant is developed? 
a) Condenser
b) Electric power system
c) Prime mover
c) Economizer
Answer: Prime mover
4. What is the main objective beyond treating feed water? 
a) To remove solid particle
b) To prevent damage by scaling
c) To speed up the steaming process
d) To control conductivity
Answer: To prevent damage by scaling
5. What is the pH value at which the boiler is alkalized? 
a) 9.0
b) 5.4
c) 6.9
d) 5.7
Answer: 9.0
6. What is the main purpose of using an economizer in a boiler?
a) To control the process of steam conversion
b) To reduce energy consumption
c) To increase the temperature of boiler
d) To maintain a constant temperature inside a boiler
Answer: To control the process of steam conversion
7. Why is air pre-heater used in the boiler? 
a) To draw in the atmospheric air
b) To increase thermal efficiency
c) To heat the air to superheated level
d) To heat the air in advance
Answer: To increase thermal efficiency
8. What is the advantage of condensing the steam? 
a) To cool down the steam
b) To discharge the same amount of feed water taken
c) Reduces the amount of pollution
d) Reduces the amount of fresh feed water
Answer: Reduces the amount of fresh feed water
9. n steam power plant which of the following component needs more maintenance: 
a) Condenser
b) Boiler
c) Turbine
d) Coal carrying system
Answer: Boiler
10. The efficiency of the electro static precipitators will be of the order: 
a) 99.6%
b) 90%
c) Turbine
d) Coal carrying system
Answer: 99.6%
11. Economizer is normally employed when boiler pressure exceeds: 
a) 70 kg/cm2
b) 50 kg/cm2
c) 30 kg/cm2
d) Can be used for all pressures
Answer: 70 kg/cm2
12. In a boiler installation the natural draught is produced ________
a) due to the fact that furnace gases being light go through the chimney giving place to cold air from outside to rush in
b) due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column
c) due to the fact that at the chimney top the pressure is more than its environmental pressure
d) all of the above
Answer: due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column
13. The draught produced by chimney of given height at given outside temperature ________
a) decreases if the chimney gas temperature increases
b) increases if the chimney gas temperature increases
c) remains same irrespective of chimney gas temperature
d) may increase or decrease
Answer: increases if the chimney gas temperature increases
14. A Fluidised bed may be defined as the bed of ______ particles 
a) Liquid
b) Solid
c) gas
d) vapour
Answer: Solid
15. The following is (are) ash handling system(s) ________
a) Hydraulic system
b) Pneumatic system
c) Steam jet system
d) All of the above
Answer: All of the above
16. The draught produced by the chimney if due to the ____ difference between the column of hot gases inside the chimney and the cold air outside. 
a) Temperature
b) Potential
c) Density
d) None of the above
Answer: Density
17. Gradually increasing temperature of flue gases at inlet tochimney for given steam outputs is an indication of ________
a) Higher effectiveness of boiler
b) High calorific value coal being burnt
c) Fouling of heat transfer surfaces
d) Raising of steam temperature
Answer: Fouling of heat transfer surfaces
18. A _________ in a boiler is used to put off fire in the furnace ofthe boiler when the level of water in the boiler falls to an unsafelimit. 
a) Blow off cock
b) Fusible plug
c) Stop valve
d) Safety valve
Answer: Fusible plug
19. For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has: 
a) More heating surface
b) Less heating surface
c) Equal heating surface
d) Heating surface depends on other parameters
Answer: More heating surface
20. A super critical boiler requires ________
a) Only preheater and superheater
b) Preheater, evaporator and superheater
c) Only preheater
d) Only superheater
Answer: Only preheater and superheater
21. The common communication protocols used in DCS include ________
a) Ethernet
b) HMI
c) Device Net
d) Control net
Answer: HMI
22. This engineering station offers powerful configuration tools that allow the user to perform engineering functions such as ________
a) creating new loops
b) trend display
c) data logging
d) communication module
Answer: creating new loops
23. Distributed individual automatic controllers are connected to field devices such as ________
a) Data Logging
b) Smart Grid
c) data acquisition
d) sensors and actuators
Answer: sensors and actuators
24. When exchanging digital signals between two different control system then (e.g. DCS DO is connected to PLC DI) ________
a) PLC Side input shall be potential free
b) Both options A and B
c) Relay doesn’t help
d) DCS side output shall be dry (e.g. Relay contact)
Answer: DCS side output shall be dry (e.g. Relay contact)
25. What is the basis on principle of automatic control of combustion is determined? 
a) Control of fuel supply to the boiler
b) Speed of rotation of fans
c) Control of combustion
d) Control of steam pressure
Answer: Control of combustion
26. When does automatic control system of combustion come into operation? 
a) When there is no fluctuation in furnace draft
b) When there is variation in steam flow rate
c) When the draft connection is clogged
d) When there is minimal amount of air supply
Answer: When there is variation in steam flow rate
27. What is the purpose of Automatic combustion control system? 
a) To get constant steam pressure
b) To maintain steady state combustion
c) To get constant steam output
d) To save the time and manual labour
Answer: To maintain steady state combustion
28. Which type of air-heater comprises of a slow-moving drum: 
a) Recuprative type
b) Regenerative type
c) Boiler tube bank
d) Furnace between water walls
Answer: Regenerative type
29. In a steam power plant heat from the flue gases is recovered in ________
a) a condenser.
b) a chimney.
c) economizer and air preheated.
d) a de-super-heater.
Answer: economizer and air preheated.
30. In a steam turbine cycle, the lowest pressure occurs in ________
a) condenser.
b) Reboiler
c) boiler.
d) super-heater.
Answer: condenser


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