Motor cycles, scooters and mopeds are not fitted with
Fuel filter
Fuel pump
Air filter
Engine lubrication
Indicate the number of valves in a single cylinder two-stroke petrol engine
One valve
Two valves
Four valves
No valves
The number of ports in the cylinder of a two stroke engine having crankcase compression and no crankcase valve are
One
Two
Three
Four
Which is the correct statement in the context of two-stroke engines?
Compression ratio is always lower than that of a four stroke cycle engine
There is only one valve for inlet and exhaust
Charge enters the engine cylinder through ports only
A diesel engine cannot operate on two stroke cycle
Compared to four-stroke cycle engine, a two-stroke cycle engine
Can be easily started
Has lesser shocks and vibrations
Has lower fuel consumption
Is smaller in size for the same output
Which aspect is not true for a two-stroke cycle engine when compared with a four stroke cycle engine?
Cycle is completed in one stroke of the piston
Uniform turning moment and hence a lighter flywheel
Theouretically develops twice the power
Noisy exhaust
More consumption of lubricating oil
The top of the piston in two-stroke engine is
Flat
Slanted
Crown shaped
Convex shaped
Scavenging air means
Air sent under compression
Air used for forcing the burnt gases out of the cylinder during the exhaust period
Forced air for cooling the engine cylinder
Burnt air containing combustion products
Which is not the feature of a petrol engine when compared with a diesel engine?
Light construction and low initial cost
Greater noise and vibration
Requires less maintenance
Greater fire risk
A diesel engine is generally more efficient than a petrol engine because of
High calorific value of diesel fuel
High compression ratio
Proper air fuel mixing and combustion
Knock-free operation
The preference of diesel engines for road transport is due to
Easy starting
Low operating cost
Low specific fuel consumption over a large range of load
Complete combustion of charge
Harmless exhaust
The specific fuel consumption per bhp-hr for a petrol engine is about
0.15 kg
0.25 kg
0.35 kg
0.5 kg
Prony brake is used for the measurement of brake power of a
Low speed engine
Low power engine
Variable speed engine
Single cylinder engine
Morse test is conducted only on
Variable speed engines
Low power engines
Multi-cylinder engines
Water cooled engines
The thermal efficiency of a well designed and properly maintained diesel engine usually lies in the range
10-15%
20-30%
35-40%
45-60%
What percentage of heat supplied in the form of fuel in a four-stroke engine is carried away by exhaust gases?
5-8%
10-15%
20-35%
40-50%
Consider the following statements:
the performance of an SI engine can be improved by increasing the compression ratio
fuels of higher octane number can be employed at higher compression ratio of these ststements
Both I and II are true
Both I and II are false
I is true but II is false
I is false but II is true
Which is not the characteristic of diesel knock in a compression ignition engine?
Instantaneous and rapid burning of the last part of the charge
Pressure rise in the clinder occurs at an enormous rate
Rough running and fatigue failure of engine components
Drop in engine power and efficiency
All of the following parameters hamper knocking tendency in a compression ignition engine, except
High inlet pressure and temperature
Higher compression ratio
Early injection of fuel
High engine load
Large engine size
Consider the following measures:
increasing the compression ratio
increasing the intake air temperature
increasing the length to diameter ratio of the cylinder
increasing the engine speed
The measures necessary to reduce the tendency to knock in CI engines would include
1, 2 and 3
1, 2 and 4
1, 3 and 4
2, 3 and 4