The efficiency of a jet propulsion unit is generally high at altitudes of
A.1000 metres
B.5000 metres
C.7500 metres
D.9000 metres
E.More than 10,000 metres
Category: Heat Engines Mcqs
Which fuel has maximum resistance to detonation
A.Toluene
B.Benzene
C.Isoctave
D.n-heptane
E.Alcohol
A closed vessel contains air at 1.2 ata and 57?C. The pressure of air in the vessel if the contents of the vessel are cooled to 37?C would be
A.2.327 ata
B.1.2 ata
C.1.127 ata
D.0.563 ata
E.0.073 ata
1 Torr is equivalent to
A.1 mm Hg
B.13.6 cm of water column
C.760 mm of water
D.760 mm of Hg
E.None of the above
Apart from reducing friction and cooling the surfaces, the function of lubricant in I.C. engines is
A.To improve thermal efficiency
B.To clean the surfaces by carrying away the carbon and metal particles cansed by wear
C.To reduce noise
D.To reduce vibrations
E.None of the above
In a compression ignition engine squish is
A.Created at the beginning of suction stroke
B.Created at the end of suction stroke
C.Created during combustion
D.Created towards the end of compression stroke
E.None of the above
The level of oil in engine cylinder should be checked when the engine is
A.Not running
B.Running
C.During starting
D.During cranking
E.None of the above
For initially dry and saturated steam flowing through a nozzle the volue of critical pressure ratio is given by
A.1
B.0.528
C.0.546
D.0.577
E.0.75
A radiation pyrometer is used for temperatures
A.Upto 100?C
B.100 – 250?C
C.250 – 500?C
D.Above 500?C
E.Below 100?C
Enthalpy of a substance is defined as
A.The sum of internal energy and the work done in forcing unit mass of substance into an enclosure at the constant pressure at which the substance exists
B.Sum of sensible heat + latent heat of substance
C.Total heat content of substance above zero degree centigrade
D.Sensible heat of water + work done in forcing unit mass of substance into an enclosure at constant pressure at which the substance exists
E.None of the above
