Steam & Related Questions (Mechanical Engineering) 3 Online Test

During…………a solid changes directly to the gaseous form without ever being a liquid
Condensation
Evaporation
Sublimation
crystalisation
For a maximum discharge of flue gases through a chimmeny, the draught h in mm of water column is equal to




Where H is height of chimney in metres an T is absolute temperature of outside air
Which is not the criterion for calculating the dimensions of a compound engine
Equal initial piston loads
Equal work output per cylinder
Equal pressure range in all stages
Equal temperature range in all stages
Consider the following statements about critical point of water latent heat is zero liquid is denser than its vapour steam generators can operate above this point Identify the correct statements using the codes given below:
1, 2 and 3
1 and 2
2 and 3
1 and 3
Given that: h is draught in mm of water H is chimney height in metres T1 is atmospheric temperature in K The maximum discharge of gases through a chimney is given by
h=
h=
h=
h=
All of the following statements about steam engines are correct, except
Piston has a maximum velocity at the centre of stroke
Steam consumption per kW-hr will be least when the engine runs at full load
Missing quantity refers to the steam not capable of expanding due to early opening of exhaust valve
In the double acting engine, more torque will be produced in the cylinder on head side
A steam nozzle is a passage of varying cross-section used in steam turbines. It converts
Enthalpy of steam into pressure energy
Enthalpy of steam into kinetic energy
Enthalpy of steam into work
Pressure energy of steam into work
Steam at exit from the nozzle has
High pressure and low velocity
High pressure and high velocity
Low pressure and low velocity
Low pressure and high velocity
The expansion process of steam through a nozzle can be approximated to
Throttling process
Free expansion process
Adiabatic process
Polytropic process
Heat supplied to steam during expansion process equals
Work done
Change in kinetic energy
Heat drop
Zero
In a varying area passage, the area A and velocity C are correlated by the expression
=(M2-1)
=(M2-1)
=(1-M)
=(1-M)
For subsonic flow through a nozzle, the following changes occure in velocity and pressure along the flow direction
Pressure decreases; velocity increases
Pressure increases; velocity decreases
Increase in both pressure and velocity
Velocity increases and pressure remains constant
In supersonic flow through nozzle, the cross sectional area is stated to decrease along the flow direction. This corresponds to following changes in pressure and velocity along the flow direction
Pressure decreases; velocity increases
Pressure increases; velocity decreases
Increase in both pressure and velocity
Velocity increases and pressure remains constant
In flow through a nozzle, the mach number is more than unity
In the converging section
At the throat
In the diverging section
Can be in any section of the nozzle depending upon the nozzle profile and geometry
Which aspect is not valid for a convergent divergent nozzle?
Subsonic flow in the convergent portion
Supersonic flow in the divergent section
Velocity of flow equals sonic velocity at the throat
Flow may reverse back from supersonic to subsonic value towards the nozzle exit
Description:

This is a 15-question test on ‘Steam: Generation, Engines and Turbines’ under a series of tests of Mechanical Engineering which is attributed to Competitive Examination Preparations e.g. IAS (Optional), GATE, IES etc.

Discussion

ashik

solution to problem 3 is wrong..

3847 days 19 hours 17 minutes ago

renjithco

DDDDDDDDDDDDDDDDDDDD

3936 days 22 hours 59 minutes ago

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