In spark ignition engines, the knocking tendency is reduced by
A.Reduction of compression ratio
B.Advancing ignition timing
C.Increasing exhaust temperature
D.Adding dope like tetra ethy lead to the fuel
E.All of the above
Category: Heat Engines Mcqs
A hydrograph is a plot of discharge through a river versus
A.Time
B.Velocity of water
C.Rate of flow of water
D.None of the above
Thermionic converters are based on
A.Seebeck effect
B.Microwave theory
C.Energy contained in thermal conductors
D.Transfer of electrons
E.None of the above
The thermal efficiency of a dual cycle engine with fixed compression ratio and fixed quantity of het and with increase in pressure ratio, will
A.Increase
B.Decrease
C.Not change
D.Depends on another factors
E.None of the above
In a lead cell battery the voltage per cell is
A.1 volt
B.1.1 volt
C.1.5 volt
D.2 volts
E.6 volts
Which spark plug will have lower heat rating
A.W 95 T1
B.W 145 T1
C.W 225 T1
D.W 300 T1
E.W 350 T1
The size of a steam engine is 200 x 250 – 300 r.p.m. In this 200 indicates
A.Horse power
B.Shaft diameter
C.Steam pressure in 1bs/sq. in.
D.Cylinder bore
E.Piston stroke
In an analysis report of a sample of coal, the percentage of one of the constituents is specified as 2.5%. This constituent could be
A.Carbon steel
B.Ash
C.Moisture
D.Sulphur
During preliminary test run of an engine for 7 hours cycles if the engine stops after operating for 5 hours then
A.The engine is rejected
B.The engine is again run for 7 hours
C.The engine in run for balance 2 hours
D.The engine is removed and another piece tested
E.None of the above
Thermal efficiency of a compression ignition engine may be of the order of
A.20%
B.35%
C.50%
D.70%
E.75%
