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Steam Boilers, Engines, Nozzles And Turbines MCQ
480 Important Steam Boilers, Engines, Nozzles And Turbines MCQ Question and Answer | PDF Free Download
1.A regenerative steam cycle renders
- AIncreased work output per unit mass of steam
- BDecreased work output per unit mass of steam
- CIncreased thermal efficiency
- DDecreased work output per unit mass of steam as well as increased thermal efficiency
2.The critical pressure gives the velocity of steam at the throat
- AEqual to the velocity of sound
- BLess than the velocity of sound
- CMore than the velocity of sound
- DNone of these
3.The diameter of fire tube of Cornish boiler compared to its shell is
- AOne half
- BOne third
- COne fourth
- DOne fifth
4.The diameter of internal flue tubes in a Lancashire boiler compared to its shell is
- AOne-half
- BOne-third
- CTwo-fourth
- DTwo-fifth
5.The aim of a compound steam engine is
- ATo reduce the ratio of expansion in each cylinder
- BTo reduce the length of stroke
- CTo reduce the temperature range in each cylinder
- DAll of the above
6.The cylinder dimensions of a compound engine may be designed on the basis of
- AEqual power developed in each cylinder for uniform turning moment
- BEqual initial piston loads on all pistons for obtaining same size of piston rod, connecting rod etc. for all cylinders
- CEqual temperature drop in each cylinder for economy of steam
- DAll of the above
7.In a glass tube type water indicator for a boiler, one end of the tube is connected to water space and the other end is connected to
- AWater space also
- BChimney
- CSteam space
- DSuperheater
8.If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by
- AThrottling calorimeter
- BSeparating calorimeter
- CCombined separating and throttling calorimeter
- DBucket calorimeter
9.For water, at pressures below atmospheric
- AMelting point rises slightly and boiling point drops markedly
- BMelting point rises markedly and boiling point drops markedly
- CMelting point drops slightly and boiling point drops markedly
- DMelting point drops slightly and boiling point drops slightly
10.The friction in the nozzle __________ exit velocity of steam.
- AHas no effect on
- BDecreases
- CIncreases
- DNone of these
11.The velocity of steam at throat of the nozzle is __________ the velocity of sound.
- AEqual to
- BLess than
- CMore than
- DNone of these
12.The ratio of the work-done on the blades per kg of steam to the total energy supplied per stage per kg of steam is called
- ABlading efficiency
- BNozzle efficiency
- CStage efficiency
- DMechanical efficiency
13.For burning 1 kg of carbon to CO as per chemically correct combustion, amount of air required is
- A1 kg
- B4/3 kg
- C8/3 kg
- D2 kg
14.The function of a piston rod is
- ATo guide motion of the piston rod and to prevent it from bending
- BTo transfer motion from the piston to the cross head
- CTo convert heat energy of the steam into mechanical work
- DTo exhaust steam from the cylinder at proper moment
15.The velocity of flue gases (V) through the chimney under a static draught of (H') metres is given by
- AV = 2g H'
- BV = 2g/H'
- CV = H'/2g
- DV = 2gH'
16.In order to reduce the rotor speed of an impulse turbine, the method employed is
- AVelocity compounding
- BPressure compounding
- CPressure-velocity compounding
- DAll of these
17.The change in internal energy in steam engines equals to
- AWork done during the Rankine cycle
- BWork done during compression
- CWork done during adiabatic expansion
- DChange in enthalpy
18.Steam turbines may be classified according to
- ADirection of steam flow
- BNumber of stages
- CMode of steam action
- DAll of these
19.The high steam and low water safety valve is used to blow off steam when the
- ASteam pressure exceeds the working pressure
- BWater level in the boiler becomes too low
- CBoth (A) and (B)
- DNone of the above
20.At critical point, i.e. p=225.65 kg/cm², the latent enthalpy of vaporisation is
- AMinimum
- BZero
- CDepends on temperature also
- Da