GATE Mechanical (ME) Test: IC Engine Performances, Carburetion, Fuel Injection,

The essential function of the carburettor in a spark ignition engine is to: 

Assertion (A): A simple or elementary carburettor provides progressively rich mixturewith increasing air flow  
Reason (R): The density of the air tends to increase as the rate of air flow increases.

Consider the following statements: 
1. In a carburettor the throttle valve is used to control the fuel supply.
2. The fuel level in the float chambers is to be about 4 to 5 mm below theorifice level of main jet.
3. An idle jet provides extra fuel during sudden acceleration.
4. A choke valve restricts the air supply to make the gas richer with fuel.
Which of the statements given above are correct?

Compensating jet in a carburettor supplies almost constant amount of petrolat all speeds because  

Consider the following statements for a carburettor:  
1. Acceleration jet is located just behind the throttle value
2. Idle jet is located close to the choke
3. Main jet alone supplies petrol at normal engine speeds
Which of the statements given above are correct?

Oxides of nitrogen in the engine exhaust can be reduced by which of the following methods?
1. Decrease in compression ratio
2. Exhaust gas recirculation
3. Use of 5% lean mixture
4. Use of oxidation catalysts in exhaust manifold
Select the correct answer using the code given below:   

Consider the following statements: 
In down draft carburettor, a hot spot is formed at the bottom wall which is common for intake and exhaust manifolds. This helps to
1. Improve evaporation of liquid fuel
2. Provide higher thermal efficiency
3. Reduce fuel consumption
4. Lower the exhaust gas temperature
Which of these statements are correct?

Where does mixing of fuel and air take place in case of diesel engine?

Consider the following statements:  
The injector nozzle of a CI engine is required to inject fuel at a sufficiently high pressure in order to
1. be able to inject fuel in a chamber of high pressure at the end of the compression stroke.
2. Inject fuel at high velocity to facilitate atomization.
3. Ensure that penetration is not high.
Of the above statements

Assertion (A): The carburetor in a petrol engine is categorized as a closed loop controlsystem.

Reason (R): There is no method by which the air-fuel ratio is measured in the carburetor.

Brake thermal efficiency of the three types of reciprocating enginescommonly used in road vehicles are given in the increasing order as

In a Morse test for a 2-cylinder, 2-stroke, spark ignition engine, the brake power was 9 kW where as the brake powers of individual cylinders with spark cut of were 4.25 kW and 3.75 kW respectively. The mechanical efficiency of the engine is 

Besides mean effective pressure, the data needed for determining the indicated power of an engine would include  

Match List-I with List-II and select the correct answer using the codes given below the lists:

The silencer of an internal combustion engine 

The three way catalytic converter cannot control which one of the following?

Which of the following symptoms shows that the combustion is necessarily complete?  

Which one of the following automobile exhaust gas pollutants is a major causeof photochemical smog?

The presence of nitrogen in the products of combustion ensures that:

An engine using octane-air mixture has N₂, O₂, CO₂, CO and H₂O as constituents in the exhaust gas. Which one of the following can be concluded?

Consider the following emissions of an IC engine: 
1. CO₂
2. HC
3. NO_x
4. Particulates
Which of these emissions cause photochemical smog?

Assertion (A): In Infrared gas analyser, the amount of absorption is the function ofconcentration of the gas and the length of the absorption path.  
Reason (R): Different gases are characterized by distinctive absorption bands withinthe infrared range.

Consider the following statements: 
Exhaust emissions of carbon monoxide from spark ignition engine is
1. mainly fuel-air mixture strength dependent
2. in the range of zero to 10%
3. measured with the help of an instrument working on the principle of nondispersiveinfra-red analysis
4. controlled by the use of a two way catalytic convertor
Which of the statements given above are correct?

Which of the following factors are responsible formation of NO, in spark ignition engine combustion:  
1. Incomplete combustion
2. High temperature
3. Availability of oxygen.
Select the correct answer.

Assertion (A): Catalytic converters for reduction of oxides of nitrogen in engineexhaust cannot be used with leaded fuels. 
Reason (R): Catalyst will be removed due to chemical corrosion by lead salts.

The discharge of hydrocarbons from petrol automobile exhaust is minimum when the vehicle is: 

Which of the following symptoms show that the combustion in air is necessarily complete?

Consider the following statements for NO_x emissions from I.C. engines:
1. Formation of NO_x depends upon combustion temperature  
2. Formation of NO_x depends upon type of coolant used
3. Exhaust gas recirculation is an effective means for control of NO_x
4. Activated Platinum is used for reduction of NO_x
Which of the statements given above are correct?

Exhaust emissions vs air fuel ratio curves for a petrol engine are shown in the given figure. The curve Crepresents  

The graph shown in the givenfigure represents the emissionof a pollutant from an SI engine for different fuel/airratios. The pollutant inquestion is