WorksheetsPower Plant Machinery - CPM Board Exam
Total questions: 50
Worksheet time: 25mins
What is the primary function of a boiler in a thermal power plant?
Generate electricity
Supply compressed air
Heat feedwater to produce steam
Condense exhaust steam
The device used to increase the pressure of air before it enters the combustion chamber is:
Superheater
Preheater
Air blower
Induced draft fan
Which of the following is a fire-tube boiler?
Babcock and Wilcox
Lancashire
Lamont
Benson
In a water-tube boiler:
Water circulates in tubes
Combustion gases circulate in tubes
Only hot air flows in tubes
No water is used
The boiler mountings include the following except:
Pressure gauge
Safety valve
Economizer
Water level indicator
The economizer is used to:
Superheat steam
Reheat steam
Reduce flue gas temperature
Preheat feedwater
What is the purpose of a superheater?
Increase boiler water temperature
Increase steam pressure
Increase steam temperature
Reduce emissions
Draft in a boiler is required to:
Increase water flow
Allow steam out
Remove ashes
Supply air for combustion
A boiler operates at 150 psi. What is this pressure in bar? (1 bar ≈ 14.5 psi)
10.3 bar
12.5 bar
8.0 bar
13.5 bar
The main cause of boiler scale formation is:
Air ingress
High pH
Dissolved minerals
Low fuel quality
In a steam turbine, steam energy is converted into:
Electrical energy
Mechanical energy
Thermal energy
Chemical energy
A reaction turbine operates on the principle of:
Newton's Second Law
Joule's Law
Action and reaction
Bernoulli's Theorem
The function of the governor in a steam turbine is to:
Control speed
Increase efficiency
Reduce steam temperature
Lubricate bearings
What is the primary function of a steam condenser?
Increase steam temperature
Convert steam into water
Heat the feedwater
Remove oxygen from water
The part that converts steam pressure into mechanical motion in a turbine is:
Rotor
Nozzle
Governor
Gland seal
Gland sealing in turbines prevents:
Oil leakage
Heat loss
Steam leakage
Condensate carryover
What is the typical rotational speed of a steam turbine connected to a 60 Hz generator?
1500 rpm
1800 rpm
3600 rpm
7200 rpm
The expansion of steam in a turbine causes:
Increase in temperature
Increase in pressure
Decrease in temperature and pressure
No change
A steam trap is used to:
Trap impurities
Drain condensate without losing steam
Filter steam
Maintain turbine speed
The efficiency of a steam turbine increases with:
Increased back pressure
Reduced superheat
Decreased exhaust pressure
Increased feedwater temperature
A centrifugal pump works on the principle of:
Reciprocating motion
Centrifugal force
Axial compression
Gravity
What component of a centrifugal pump converts velocity into pressure?
Impeller
Diffuser
Shaft
Motor
Cavitation in pumps is caused by:
High speed
High temperature
Low pressure at the suction side
Over-lubrication
A reciprocating pump is classified as:
Dynamic
Positive displacement
Rotary
Jet pump
Which pump is commonly used for boiler feedwater?
Jet pump
Centrifugal pump
Reciprocating pump
Gear pump
Which compressor is best suited for high-pressure applications?
Axial compressor
Centrifugal compressor
Reciprocating compressor
Rotary compressor
The volumetric efficiency of a reciprocating compressor is defined as:
Discharge volume / Swept volume
Actual suction volume / Swept volume
Swept volume / Clearance volume
Discharge pressure / Suction pressure
Intercooling in multistage compressors helps in:
Increasing power input
Reducing work required
Increasing pressure
Increasing flow rate
A vacuum pump is used to:
Increase pressure
Remove air/gases
Condense steam
Pump viscous fluids
The pressure ratio of a compressor is defined as:
Suction pressure / Discharge pressure
Discharge pressure / Suction pressure
Absolute pressure / Gauge pressure
Gauge pressure / Absolute pressure
The heat rate of a power plant is defined as:
Heat input per unit of electricity generated
Electricity generated per fuel input
Heat transferred per kg of water
Power consumed by auxiliaries
The purpose of a deaerator is to remove:
Dirt from water
Salts from steam
Oxygen and other dissolved gases
Oil from condensate
In lubrication systems, the most common lubricant is:
Water
Synthetic polymer
Grease
Oil
The main function of a heat exchanger is:
Heat generation
Heat removal
Heat transfer between fluids
Convert heat to electricity
Preventive maintenance is carried out:
After a breakdown
As per schedule
Randomly
Only during shutdowns
Vibration in rotating machinery indicates:
Proper operation
Over-speed
Misalignment or imbalance
Overheating
The generator converts:
Mechanical to electrical energy
Electrical to mechanical energy
Heat to mechanical energy
Fuel to electricity directly
Which instrument measures steam flow?
Thermometer
Orifice meter
Rotameter
Venturimeter
What is the function of the cooling tower in a thermal power plant?
Cool generator windings
Cool lubricating oil
Cool steam into water
Cool circulating water
Transformer in power plants is used to:
Step down voltage
Step up voltage
Regulate frequency
Convert AC to DC
The main fuel used in coal-fired power plants is:
Diesel
Anthracite
Peat
Bitumen
A combined cycle power plant uses:
Coal and steam
Gas turbine and steam turbine
Nuclear and fossil fuels
Wind and solar
The term "black start" refers to:
Restarting from complete shutdown without grid support
Starting in the dark
Generator synchronization
Emergency lighting
The backup power system in power plants is typically a:
Transformer
Turbine
Diesel Generator (DG) set
Boiler
PPE for working near steam pipelines must include:
Safety boots only
Gloves and goggles only
Full-body heat resistant suit
Earplugs only
Lockout-Tagout (LOTO) is a procedure used for:
Equipment startup
Safety during maintenance
Employee training
Boiler blowdown
The instrument used to measure electric power is:
Ammeter
Wattmeter
Voltmeter
Megger
A power factor closer to 1.0 indicates:
Poor efficiency
High reactive power
Better energy efficiency
Low voltage
Which of the following is a renewable power plant?
Diesel power plant
Hydro power plant
Nuclear power plant
Thermal power plant
What is the ideal boiler efficiency range for a well-maintained thermal power plant?
40-50%
60-70%
70-85%
85-95%
