Explore topic-wise MCQs in Mechanical Engineering.

This section includes 760 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.

551.

_Which of the following boilers is best suited to meet fluctuating demands?$?

A. Babcock and Wilcox
B. Locomotive
C. Lancashire
D. Cochran
Answer» C. Lancashire
552.

_Which is not correct statement about the function of furnace?$?

A. To provide proper conditions for continuous complete combustion
B. Mix fuel with air and ignite
C. Separate ash from coal
D. Maintain heat supply to prepare and ignite the incoming fuel
Answer» D. Maintain heat supply to prepare and ignite the incoming fuel
553.

_For water, at pressures below atmospheric;$?

A. Melting point rises slightly and boiling point drops markedly
B. Melting point rises markedly and boiling point drops markedly
C. Melting point drops slightly and boiling point drops markedly
D. Melting point drops slightly and boiling point drops slightly
Answer» B. Melting point rises markedly and boiling point drops markedly
554.

_The flow of steam is supersonic$?

A. At the entrance to the nozzle
B. At the throat of the nozzle
C. In the convergent portion of the nozzle
D. In the divergent portion of the nozzle
Answer» E.
555.

_There is always some steam left in the clearance space from the previous stroke. This steam left in the clearance space is called$?

A. Wet steam
B. Saturated steam
C. Superheated steam
D. Cushion steam
Answer» E.
556.

_For maximum discharge through a chimney, the condition is that height of hot gas column producing the draught should be$?

A. One-half the height of chimney
B. Equal to the height of chimney
C. Two times the height of chimney
D. Four times the height of chimney
Answer» C. Two times the height of chimney
557.

_The function of a piston rod is$?

A. To guide motion of the piston rod and to prevent it from bending
B. To transfer motion from the piston to the cross head
C. To convert heat energy of the steam into mechanical work
D. To exhaust steam from the cylinder at proper moment
Answer» C. To convert heat energy of the steam into mechanical work
558.

_The high steam and low water safety valve is used to blow off steam when the$?

A. Steam pressure exceeds the working pressure
B. Water level in the boiler becomes too low
C. Both (A) and (B)
D. None of the above
Answer» D. None of the above
559.

_Which of the following is a fire tube boiler?$?

A. Locomotive boiler
B. Babcock and Wilcox boiler
C. Stirling boiler
D. All of the above
Answer» B. Babcock and Wilcox boiler
560.

_The actual vacuum in a condenser is equal to$?

A. Barometric pressure + actual pressure
B. Barometric pressure - actual pressure
C. Gauge pressure + atmospheric pressure
D. Gauge pressure - atmospheric pressure
Answer» C. Gauge pressure + atmospheric pressure
561.

_Pick up wrong statement about desired properties of a good fuel$?

A. High calorific value
B. Produce minimum smoke and gases
C. Ease in storing
D. High ignition point
Answer» E.
562.

Fire tube boilers are limited to a maximum working pressure of$?

A. 0.17 MN/m²
B. 1.7 MN/m²
C. 17 MN/m²
D. 170 MN/m²
Answer» C. 17 MN/m¬¨‚â§
563.

Natural water circulation, by convection in water tube boilers, with increase in pressure of boiler$?

A. Increases
B. Decreases
C. Remain unaffected
D. First increases and then decreases
Answer» C. Remain unaffected
564.

In a Woolf type compound engine, the high pressure and low pressure cylinders$?

A. Have common piston rod
B. Are set at 90°
C. Have separate piston rod
D. Are set in V arrangement
Answer» D. Are set in V arrangement
565.

The increase in pressure$?

A. Lowers the boiling point of a liquid
B. Raises the boiling point of a liquid
C. Does not affects the boiling point of a liquid
D. Reduces its volume
Answer» C. Does not affects the boiling point of a liquid
566.

The difference between Cornish boiler and Lancashire boiler is that$?

A. Former is fire tube type and latter is water tube type boiler
B. Former is water tube type and latter is fire tube type
C. Former contains one fire tube and latter contains two fire tubes
D. None of the above
Answer» D. None of the above
567.

The size of a boiler drum in pulverized fuel fired boiler, as its size and capacity, (steam pressure and flow ratings) increase$?

A. Increases
B. Decreases
C. Remains unchanged
D. Increases/decreases depending on steam temperature requirements
Answer» C. Remains unchanged
568.

Which of the following boiler is best suited to meet the fluctuating demand of steam?$?

A. Locomotive boiler
B. Lancashire boiler
C. Cornish boiler
D. Babcock and Wilcox boiler
Answer» B. Lancashire boiler
569.

The pressure of steam in the engine cylinder at the beginning of the stroke is ________ the boiler pressure.$?

A. Equal to
B. Less than
C. Higher than
D. None of these
Answer» C. Higher than
570.

At which pressure the properties of water and steam become identical$?

A. 0.1 kg/cm²
B. 1 kg/cm²
C. 100 kg/cm²
D. 225.6 kg/cm²
Answer» E.
571.

The high pressure and low pressure cylinders in a Woolf type compound engine are regarded as having cranks$?

A. 180° to each other
B. 90° to each other
C. 0° to each other
D. None of these
Answer» B. 90¬¨‚àû to each other
572.

1 kg.m is equal to$?

A. 9.81 Joules
B. 102 Joules
C. 427 Joules
D. None of these
Answer» B. 102 Joules
573.

Stage efficiency is also known as$?

A. Diagram efficiency
B. Nozzle efficiency
C. Gross efficiency
D. None of these
Answer» D. None of these
574.

The fittings mounted on the boiler for its proper and safe functioning is a$?

A. Water level indicator
B. Pressure gauge
C. Safety valve
D. All of these
Answer» E.
575.

Steam in water tube boiler as compared to fire tube boiler$?

A. Can be raised rapidly
B. Is raised at slower rate
C. Is raised at same rate
D. Could be raised at fast/slow rate depending on design
Answer» B. Is raised at slower rate
576.

In a boiler, the heat is lost$?

A. To dry flue gases
B. In moisture present in the fuel
C. To steam formed by combustion of hydrogen per kg of fuel
D. All of the above
Answer» E.
577.

The best suited coal for chain or traveling grate stoker boiler is$?

A. Coking coal
B. Non-coking or free burning coal
C. Pulverized coal
D. High sulphur coal
Answer» C. Pulverized coal
578.

The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.$?

A. More
B. Less
C. Same
D. None of these
Answer» C. Same
579.

A compound steam engine in which piston rods of high pressure and low pressure cylinders ' are attached to two different cranks set at 180° to each other, is called$?

A. Receiver type compound engine
B. Tandem type compound engine
C. Woolf type compound engine
D. Both (A) and (B)
Answer» D. Both (A) and (B)
580.

Ultimate analysis of fuel is determination of percentage of$?

A. Carbon, hydrogen, nitrogen, sulphur, moisture
B. Fixed carbon, ash, volatile matter, moisture
C. Higher calorific value
D. Lower calorific value
Answer» B. Fixed carbon, ash, volatile matter, moisture
581.

It is required to produce large amount of steam at low pressure. Which boiler should be used?$?

A. Pulverized fuel fired boiler
B. Cochran boiler
C. Lancashire boiler
D. Babcock and Wilcox boiler
Answer» D. Babcock and Wilcox boiler
582.

A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as$?

A. Superheater
B. Air-preheater
C. Economizer
D. Injector
Answer» C. Economizer
583.

In a receiver type compound engine, the high pressure and low pressure cylinders$?

A. Have common piston rod
B. Are set at 90°
C. Have separate piston rods
D. Are set in V-arrangement
Answer» D. Are set in V-arrangement
584.

Sublimation region is the region where$?

A. Solid and vapor phases are in equilibrium
B. Solid and liquid phases are in equilibrium
C. Liquid and vapor phases are in equilibrium
D. Solid, liquid and vapor phases are in equilibrium
Answer» B. Solid and liquid phases are in equilibrium
585.

The draught produced by a steam jet issuing from a nozzle placed in the chimney is called$?

A. Induced steam jet draught
B. Chimney draught
C. Forced steam jet draught
D. None of these
Answer» B. Chimney draught
586.

The draught produced by a steam jet issuing from a nozzle placed in the ash-pit under the fire grate of the furnace is called$?

A. Induced steam jet draught
B. Chimney draught
C. Forced steam jet draught
D. None of these
Answer» D. None of these
587.

The cylinder condensation or missing quantity may be reduced by$?

A. The efficient steam jacketing of the cylinder walls
B. Superheating the steam supplied to the engine cylinder
C. Keeping the expansion ratio small in each cylinder
D. All of the above
Answer» E.
588.

The dry saturated steam at very low pressure, (510 kg/cm²) when throttled to atmosphere will become$?

A. Wet
B. Superheated
C. Remain dry saturated
D. Dry
Answer» C. Remain dry saturated
589.

The safety valve at superheater as compared to drum safety valve setting is set at$?

A. Higher value
B. Lower value
C. Same value
D. Any value
Answer» C. Same value
590.

Equivalent evaporation is the amount of water evaporated in a boiler from and at$?

A. 0°C
B. 100°C
C. Saturation temperature at given pressure
D. Room temperature
Answer» C. Saturation temperature at given pressure
591.

The length of Cornish boiler varies from$?

A. 2 to 4.5 m
B. 3 to 5 m
C. 5 to 7.5 m
D. 7 to 9 m
Answer» D. 7 to 9 m
592.

The amount of water evaporated from feed water at _________ into dry and saturated steam at 100° C at normal atmospheric pressure is called equivalent evaporation from and at 100° C.$?

A. 0°C
B. 40°C
C. 60°C
D. 100°C
Answer» E.
593.

A compound steam engine in which the high pressure and low pressure cylinders have common piston rod, is called$?

A. Receiver type compound engine
B. Tandem type compound engine
C. Woolf type compound engine
D. None of these
Answer» C. Woolf type compound engine
594.

Locomotive boiler is a$?

A. Single tube, horizontal, internally fired and stationary boiler
B. Single tube, vertical, externally fired and stationary boiler
C. Multi-tubular, horizontal, internally fired and mobile boiler
D. Multi-tubular, horizontal, externally fired and stationary boiler
Answer» D. Multi-tubular, horizontal, externally fired and stationary boiler
595.

Which is not the correct statement about moisture in coal?$?

A. Inherent moisture and surface moisture are different things
B. In some coals moisture may be present up to 40%
C. Some moisture in coal helps in better burning which is not possible with completely dry coal
D. It increases thermal efficiency
Answer» E.
596.

Benson boiler requires$?

A. No drum
B. One drum
C. Two drums
D. Three drums
Answer» B. One drum
597.

O‚ÇÇ content in atmospheric air on volume basis is$?

A. 21 %
B. 23 %
C. 30 %
D. 40 %
Answer» B. 23 %
598.

In case of non-condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the condenser pressure.$?

A. Equal to
B. Lower than
C. Higher than
D. None of these
Answer» D. None of these
599.

The actual power supplied by the engine crankshaft is called$?

A. Indicated power
B. Brake power
C. Frictional power
D. None of these
Answer» C. Frictional power
600.

Heating wet steam at constant temperature is heating it at constant$?

A. Volume
B. Pressure
C. Entropy
D. Enthalpy
Answer» C. Entropy