Chapter 6 · MCQ Read Mode

Fuel Supply System and Ignition System

The chemically correct air-fuel ratio for petrol is about:

The mixture required for maximum power in an SI engine is approximately:

The mixture required during idling is rich mainly because of:

An extremely rich mixture is required during cold starting because:

The 10% point of the petrol distillation curve mainly indicates:

In a carburettor, fuel is drawn into the air stream because:

The function of the float and needle valve in a carburettor is to:

In a simple carburettor, as air flow through the venturi increases, the mixture:

The accelerating pump in a carburettor is used to:

The choke valve in a carburettor is used for:

The device that keeps the mixture strength nearly constant over the cruising range is the:

A carburettor in which a piston varies the venturi area to keep a constant depression is the:

A major drawback of a carburettor in multi-cylinder engines is:

In a multipoint fuel injection system, fuel is injected:

In single-point (throttle-body) injection, the intake manifold carries:

The quantity of fuel injected by an electronic solenoid injector is mainly controlled by:

The sensor that enables closed-loop control of the air-fuel ratio around λ = 1 is the:

The sensor used by the ECU to determine engine speed and crank position is the:

Injection in which each injector is timed individually to the intake stroke of its cylinder is called:

In gasoline direct injection, fuel is injected:

GDI engines can use a higher compression ratio mainly because:

Stratified-charge operation in GDI engines improves part-load economy mainly by:

A known problem of GDI engines is:

Cutting off fuel injection during deceleration (overrun) is possible with:

The ignition coil in a battery ignition system works as a:

The condenser connected across the contact-breaker points:

The distributor shaft of a four-stroke engine rotates at:

In a battery (coil) ignition system, the spark voltage at high speeds tends to:

A magneto ignition system gives a weak spark:

Capacitor discharge ignition (CDI) uses a/an:

In a waste-spark distributorless ignition system of a four-cylinder engine:

The centrifugal advance mechanism advances the spark with increase in:

The vacuum advance mechanism provides more spark advance at:

The most important factor influencing flame speed in an SI engine is:

Knock in an SI engine is caused by:

Which of the following REDUCES knock in an SI engine?

A cold spark plug is suitable for:

The ignition quality of diesel fuel is expressed by its:

Load in a CI engine is controlled by varying:

In a jerk-type (Bosch) fuel pump, the quantity of fuel delivered is varied by:

The delivery valve in a diesel fuel pump helps to:

A fuel system in which the pump and nozzle are combined in one unit for each cylinder is the:

Multi-hole nozzles are generally used in:

In a common-rail system, the injection pressure:

The main purpose of pilot injection in CRDI engines is to:

The stage of CI combustion in which fuel accumulated during the delay burns rapidly is the:

The ignition delay in a CI engine decreases with:

Diesel knock is mainly caused by:

Compared with IDI engines, direct-injection diesel engines have:

A Ricardo Comet combustion chamber is a:

The most important property of a lubricating oil is its:

In the oil designation SAE 10W-30, '10W' refers to:

Engine oils for diesel engines are classified by API with the letter:

A high total base number (TBN) in engine oil is needed to:

The lubrication system used in most modern automobile engines is:

In a dry-sump lubrication system, oil is stored in:

Two-stroke petrol engines are usually lubricated by:

Over-cooling of an engine results in:

The thermostat in the cooling system:

The pressure cap on a radiator:

Compared with liquid cooling, air cooling is:

The most commonly used antifreeze in engine coolant is:

The main objective of supercharging an engine is to:

Supercharging is especially useful for engines operating at high altitude because it:

Supercharging an SI engine generally increases its tendency to:

Supercharging a CI engine tends to:

A turbocharger is driven by:

A Roots blower differs from a screw supercharger in that the Roots blower:

The wastegate of a turbocharger is used to:

The delay in the build-up of boost pressure when the accelerator is pressed is called:

An intercooler is fitted after a turbocharger to:

An arrangement in which a small turbo operates at low speed and a second turbo is brought in at high speed is:

Carbon monoxide in SI engine exhaust is mainly due to:

NOx formation in engines is mainly due to:

A major source of unburnt HC in SI engines is:

Black smoke from a diesel engine usually indicates: