Rankine cycle comprises of two isothermal and two __________ processes.
Isobaric
Polytropic
Isentropic
None of these
Correct Answer :
D. None of these
Related Questions
Out of the following substances, one ton of __________ will store the maximum heat for a rise of 30°C in temperature.
Steel
Lignite
Water
Lime stone
Consideration of the creep is the most important in case of the
Blades of gas turbine
Piston of an I. C. engine
Flywheel of steam engine
Cycle chain
High endurance limit of carburised machine parts is because of the fact that carburisation
Suppresses any stress concentration produced in the parts
Enhances the yield point of the material
Introduces a compressive layer on the surface
Produces a better surface finish
During sensible heating of humid air
Relative humidity increases
Dew point remains constant
Dry bulb & wet bulb temperature increases
Both 'b' & 'c'
The elastic strain in copper is due to the
Motion of dislocations
Stretching of atomic bonds
Breakage of atomic bonds
None of the above
Gage pressure within a spherical droplet of a fluid is 'p'. What will be gage pressure within a bubble of the same size & of the same fluid?
p
2 p
0.5 p
0.25 p
Principal alloying element in Elinvar (used for making hair springs for watches) is
Copper
Aluminium
Nickel
Zinc
The activity of pure hydrogen gas at 1000°C and 5 atm pressure
Is always less than 1
Is always greater than 1
Can be 5
Depends on the choice of the standard state
Blow off cock is provided in steam boiler to
Guard the boiler in case of abnormal rise in steam pressure
Drain out water and sludge during its repair
Regulate the supply of water in boiler
Put out the fire in the furnace when the water level in the boiler falls to unsafe limit
Iron content in Indian iron ore is about __________ percent.
80-85
60-65
40-45
20-25
The best lubricants for a machine working at high temperature & load is
Grease
Solid lubricant
Animal oils
Mineral oils
Which one can be directly solidified from gaseous state without entering into liquid state?
Helium
Oxygen
Carbon dioxide
None of these
Mild steel has __________ crystal lattice structure.
Face centred cubic (fcc)
Body centred cubic (bcc)
Orthorhombic
Cubic
Heating the Hypo-eutectoid steels to 30°C above the upper critical temperature line, soaking at that temperature and then cooling slowly to the room temperature to form a pearlite & ferrite structure is called
Tempering
Hardening
Annealing
Normalising
__________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical.
Mach
Reynolds
Froude
Weber
Increasing the carbon content of steel
Reduces the upper shelf energy
Increasing the ductility transition temperature
Decreases brittleness
Decreases hardness
Superheating of steam is done at constant
Enthalpy
Entropy
Pressure
Volume
One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m- 1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is
100
900
9000
10000
A material being tested for endurance strength is subjected to the __________ load.
Impact
Completely reversed
Dynamic
Static & dynamic
Closeness of packing is maximum in case of __________ crystal lattice.
Face centred
Simple cubic
Body centred
None of these
As per international norms, the maximum permissible value of noise level in the industrial environment is __________ decibels as measured at a distance of 1.5 metres from the source of noise.
110
85
60
45
Cold heading or upsetting is categorised as the __________ process.
Extrusion
Bending
Rolling
Forging
Increasing sulphur content in pig iron tends to make it
Soft
Hard
Tough
Ductile & malleable
In TIG welding, thoriated tungsten electrodes are used, because it
Has higher current carrying capacity
Has better electron emissivity
Is stronger than ordinary tungsten
Is easy to prepare
On oscilloscope screen for dynamic measurement, lissajous diagram is normally used to determine the __________ of the input signal.
Frequency
Amplitude
Damping
None of these
Auto collimator is used to check
Flatness
Angle
Rotor balancing
Roughness
Which of the following is an ore dressing operation?
Classification
Smelting
Roasting
None of these
Corrosion rate cannot be lowered by reducing the __________ of the corroding medium.
Concentration
Velocity
Temperature
None of these
Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to
Achieve very high purity of aluminium (99.9%)
Keep the electrolyte in liquid condition by the generation of heat
Electrolytically dissociate alumina
Both (B) & (C)
High relative humidity decreases the evaporative process and as the temperature is increased, the relative humidity decreases. The comfort range for human body is the ambient temperature of 22 to 27°C with relative humidity ranging from __________ percent.
5 to 10
15 to 25
45 to 50
75 to 80