Pick up the false statement
A. Thermal efficiency of diesel engine is about 34%
B. Theoretically correct mixture of air and petrol is approximately 15 : 1
C. High speed compression engines operate on dual combustion cycle
D. S.I. engines are quality governed engines
Answer: Option D
Solution(By Examveda Team)
In this system of governing, the quality of charge (i.e. air-fuel ratio of the mixture) is kept constant. But the quantity of mixture supplied to the engine cylinder is varied by means of a throttle valve which is regulated by the centrifugal governor through rack and pinion arrangement.This Question Belongs to Mechanical Engineering >> Internal Combustion Engines (I.C. Engines)
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Comments ( 4 )
Engine pistons are usually made of aluminium alloy because it
A. Is lighter
B. Wear is less
C. Absorbs shocks
D. Is stronger
The reason for supercharging in any engine is to
A. Increase efficiency
B. Increase power
C. Reduce weight and bulk for a given output
D. Effect fuel economy
Morse test can be conducted for
A. Petrol engines
B. Diesel engines
C. Multi cylinder engines
D. All of these
The cetane (C16H34) which is a straight chain paraffin, is assigned a cetane number of
A. 0
B. 50
C. 100
D. 120
Carburated Petrol Engine uses Quantitative Governing. Carburated Petrols use Quantitative Governing since Air Fuel Quality is pre-determined & varying quantity through Throttle Valve determines combustion.
Whereas Diesels works on Excess Air Cycle & varying Quality of Fuel Air mixture inside the cylinder determines combustion.
Diesel efficiency is 70 or 34
Options 1 is also incorrect..Thermal efficiency of diesel engine is 70% while petrol engine is 30%
why not a?...can anyone explain this