One of the major exhaust emission from CI engines compared to SI engine is
Decrease in air – fuel ratio in SI engine results in
NOx emission in SI engine will be lowest during
Photochemical smog is mainly due to
Thermal convertors cannot reduce emission of
Exhaust gas recirculation has the disadvantage of
Three way catalytic converter reduces emission of
Lead compounds were added in gasoline to
Advantage of gaseous fuel is that
Paraffin’s are generally represented by
Octane no of Iso octane is
Iso octane has
Crude oil is separated into gasoline, kerosene & fuel oil by:-
In a SI engine, which one of the following is the correct order of the fuels with increasing detonation tendency?
The presence of Nitrogen in the products of combustion ensures that
The objective of supercharging an engine is:
1. To reduce space occupied by the engine
2. To increase the power output of an engine when greater power is required
Which of the above statements are correct?
Consider the following statements regarding supercharging of CI engines:
1. Supercharging results in quieter and smoother operation of a CI engine
2. Supercharging of a CI engine requires increase in valve overlap
3. The limit of supercharging for a CI engine is reached by thermal and mechanical loading
Which of the above statements are correct?
Consider the following statements with regard to IC engine
1. For best fuel economy of spark ignition engines, the fuel-air mixture should be lean.
2. With supercharging, the specific fuel consumption in compression ignition engines increases
3. With increase of load, knocking tendency in compression ignition engines decreases
Which of the above statements are correct?
Consider the following statements pertaining to supercharging of engines:
1. The power output for a given engine increases.
2. The loss of power due to altitude is compensated.
3. The increase in supercharging pressure decreases the tendency to detonate in spark ignition engines.
4. The mechanical efficiency of supercharged engines is quite high compared to naturally aspirated engines
Which of the above statements are correct?
Consider the following statements for a combustion process:
1. The total mass of each chemical element in the reactants is preserved in the products
2. The presence of carbon monoxide in the products of combustion implies incomplete combustion
Which of the above statements is/are correct?
Oxides of nitrogen in Petrol engine exhaust can be reduced by the following methods:
1. Use of 5% lean mixture
2. Advancing the spark timing
3. Recirculating a fraction of exhaust gases
4. Using an oxidation catalyst in the exhaust manifold
Which of the above statements is/are correct?
Consider the following statements regarding supercharging of Diesel engines:
1. The mechanical efficiency of a supercharge Diesel engine is slightly better than that of naturally aspirated engine.
2. There is reduction in smoke in the case of supercharged engine in the overload operation.
Which of the above reasons is/are correct?
In Diesel engines, the control of black smoke in exhaust can be achieved by:
1. Running the engine at lower load
2. Maintaining the injection system perfect.
3. Using Diesel fuel of higher Cetane number.
Which of the above statements are correct?
Which of the following remarks pertaining to supercharging of IC engines are correct?
1. Ideal supercharging increases the output but decreased the thermal efficiency slightly
2. The indicated mean effective pressure and mechanical efficiency increase with supercharging
3. The permissible amount of supercharging depends on the compression ratio, air-fuel mixture and design of engine.
4. Engine friction losses increases with supercharging
In spark ignition petrol engines maximum emission of NOX takes place when the air fuel ratio (A/F) is
