Explore topic-wise MCQs in Uncategorized topics.

This section includes 471 Mcqs, each offering curated multiple-choice questions to sharpen your Uncategorized topics knowledge and support exam preparation. Choose a topic below to get started.

351.

In this carburetor, air lifts fuel droplets against gravity.

A. updraught
B. downdraught
C. side draught
D. cross draught
Answer» B. downdraught
352.

The tip of the nozzle is kept

A. at the same level as that of fuel in float chamber
B. at level above the fuel level in float chamber
C. at level below the fuel level in float chamber
D. sometimes above, sometime below the fuel level in float chamber
Answer» C. at level below the fuel level in float chamber
353.

GDI refers to injection of fuel

A. near the inlet port
B. into the intake manifold
C. directly into the cylinder
D. none of the above
Answer» D. none of the above
354.

To reduce detonation, the spark plugh should be located

A. near to intake valve
B. at the corner
C. centrally
D. neat piston
Answer» D. neat piston
355.

Which is not a probable location of preignition?

A. spark plugh tip
B. exhaust valve
C. remote corner of chamber
D. intake valve
Answer» E.
356.

When SI engine is Idling

A. leaner mixture is required
B. mixture close to stoichiometric condition is needed
C. richer mixture is required
D. it may vary with atmospheric condition
Answer» D. it may vary with atmospheric condition
357.

what would be the mass flow rate of gasoline in kg/s, if the engine consumes 8lit/hr, taking the specific gravity of the gasoline is 0.8

A. 0.00178
B. 0.00168
C. 0.1234
D. 0.4321
Answer» B. 0.00168
358.

Stoichiometric air-fuel ratio of petrol engine is roughly

A. 18/1
B. 25/1
C. 15/1
D. 10/1
Answer» D. 10/1
359.

Transient conditions in SI engine occurs because of

A. evaporation of fuel is incomplete
B. quantity of fuel in intake manifold may be increasing or decreasing
C. both a and b
D. none of the above
Answer» D. none of the above
360.

Stoichiometric condition in S I Engine is such that

A. it creates some pollutants with combustion of fuel and air mixture
B. it gives complete combustion of the air fuel mixture
C. exact quantity of the air is mixed with fuel to burn mixture effectively
D. both b and c
Answer» E.
361.

what is the density of the fuel whose specific gravity is 0.8

A. 800 kg/ cubic meter
B. 780 cubic meter
C. 850 cubic meter
D. 810 cubic meter
Answer» B. 780 cubic meter
362.

Now a days a unleaded petrol is in the market because

A. it has better anti knock property
B. it is cheaper as compared to leaded petrol
C. lead deposits are poisonous
D. it is highly refined petrol
Answer» D. it is highly refined petrol
363.

Fuel flow rate as per demand is varied by varying pressure difference in _____ carburetor.

A. su
B. apha
C. solex
D. none of the above
Answer» D. none of the above
364.

non dispersive infrared analyzer is widely accepted instrument for measuring

A. unburned hydrocarbons
B. carbone monoxide
C. carbone dioxide
D. nox
Answer» C. carbone dioxide
365.

chemilumme scence analyzer is used for measuring

A. hc
B. co
C. nox
D. co2
Answer» D. co2
366.

The correct expression for nozzle lip is

A. tip height fuel surface height
B. tip height throat height
C. throat height float chamber height
D. fuel surface height
Answer» B. tip height throat height
367.

The chemically correct mixture for petrol is approximately

A. 1970-01-01 12:01:00
B. 1970-01-01 15:01:00
C. 1970-01-01 17:01:00
D. 1970-01-01 18:01:00
Answer» C. 1970-01-01 17:01:00
368.

A carburettor is used in case of

A. gas engines
B. petrol engines
C. diesel engines
D. none of the above
Answer» C. diesel engines
369.

Idling condition of the SI engine is

A. when engine is running but no power out put from crank shaft
B. when engine is running but power is produced from crankshaft
C. when engine is not running but power out put from crank shaft
D. only crankshaft is rotating
Answer» B. when engine is running but power is produced from crankshaft
370.

The function of carburettor is to control,

A. speed
B. a:f ratio
C. a:f ratio and quantity of mixture
D. none of the above
Answer» E.
371.

Transient condition of SI engine is

A. idling
B. cruising
C. starting
D. maximum power range
Answer» D. maximum power range
372.

Idling of engine refers to

A. no load
B. 0-20% load
C. 20-40 % load
D. none of the above
Answer» B. 0-20% load
373.

the spark timing and combustion rate should be should be such that

A. one half of the total pressure occurs at tdc
B. ignition delay is reduced
C. peak pressure occurs at tdc
D. none of the above
Answer» B. ignition delay is reduced
374.

In port injection system, location of injector is

A. inside cylinder near intake port
B. near carburetor
C. inside intake manifold near intake port
D. inside cylinder near exhaust port
Answer» D. inside cylinder near exhaust port
375.

Simple carburetor doesn't have which of the following element in its arrangement

A. float chamber
B. auxiliary air port
C. venturi
D. throttle valve
Answer» C. venturi
376.

Petrol engines are

A. quality governed
B. mechanically governed
C. quantity governed
D. all of the above
Answer» D. all of the above
377.

Simple carburetor can be used for following applications

A. engine running at constant speed with load varying on engine
B. engine running at constant speed without load varying on engine
C. engine running at varying speed without load varying on engine
D. engine running at very very low speed without load varying on engine
Answer» C. engine running at varying speed without load varying on engine
378.

In complete caruretor, idling passage opens in a draft tube at which position?

A. engine side of throttle valve
B. venturi side of throttle valve
C. at the venturi
D. none of the above
Answer» B. venturi side of throttle valve
379.

Jet tube in simple carburetor is also called as

A. choke tube
B. venturi tube
C. both a and b
D. only a
Answer» D. only a
380.

Which of the following is not necessary condition for starting of combustion process in SI engines?

A. compression of charge
B. presence of fuel
C. presence of oxygen
D. formation of spark
Answer» B. presence of fuel
381.

in the air base method of measuring air flow, the air base is provided to

A. damp out the pulsations
B. have constant temprature
C. have constant flow
D. provide constant velocity of flow
Answer» D. provide constant velocity of flow
382.

what would be the mass flow rate of the air, if the air consumption time for 0.1 cubic meter as 16.3 sec whose density is 1.175 kg per cubic meter

A. 0.00821 kg/sec
B. 0.00531 kg/sec
C. 0.00231 kg/se
D. 0.00721 kg/se
Answer» E.
383.

Nozzle lip is provided in simple carburetor

A. to avoid overflow of liquid fuel from float chamber
B. to get proper working of simple carburetor
C. to maintain proper vapor quantity produced in simple carburetor
D. to maintain liquid level in float chamber
Answer» B. to get proper working of simple carburetor
384.

Carburetor which uses horizontal draft tube is called

A. up draught carburetor
B. down draught carburetor
C. side draught carburetor
D. none of the above
Answer» D. none of the above
385.

Mixture requirements at different load and speeds of petrol engine are

A. starting and idling
B. acceleration
C. part load running
D. all of the above
Answer» E.
386.

The function of carburettor is,

A. to control a:f ratio
B. to control amount of mixture
C. to control both a and b
D. none of the above
Answer» E.
387.

During idling condition of SI engine mixtue is diluted because of exhaust gases presence in cylinder, so fuel is provided in venturi tube

A. at throat section because of suction created at that point
B. after throttle valve because of suction created at that point
C. after throat section because of suction created at that point
D. after choke valve because of suction created at that point
Answer» C. after throat section because of suction created at that point
388.

The function of the venturi in the carburetor is

A. to decrease fuel flow
B. to increase fuel flow
C. to decrease air velocity
D. to increase air velocity
Answer» E.
389.

which of the following factor will not assist in improving thermal efficiency of a compression ignition engine

A. fine atomisation and even distribution of fuel
B. miniumum heat loss during combustion
C. clear exhaust
D. high surgace to volume ratio
Answer» E.
390.

A venturi of fixed dimension is used in

A. constant choke carburetor
B. constant vacuum carburetor
C. multiple venturi carburetor
D. multijet carburetor
Answer» B. constant vacuum carburetor
391.

The venturi is the portion in a draft tube

A. converging section
B. diverging section
C. minimum cross secional area
D. all of the above
Answer» D. all of the above
392.

The combustion will not start immediately after spark because of

A. flame propogation
B. after burning
C. ignition lag
D. motoring
Answer» D. motoring
393.

During idling, mixture provided by simple carburetor is

A. increasingly rich
B. increasingly lean
C. lean
D. chemically correct
Answer» D. chemically correct
394.

During acceleration, mixture provided by simple carburetor is

A. increasingly rich
B. increasingly lean
C. lean
D. chemically correct
Answer» D. chemically correct
395.

Simple carburetor provides correct quality of mixture

A. at all operating conditions
B. during acceleration only
C. during cruising only
D. only at one throttle position
Answer» E.
396.

The choke valve is placed in a draft tube

A. on atmospheric side of the venturi
B. on engine side of the venturi
C. at the venturi
D. none of the above
Answer» B. on engine side of the venturi
397.

Main suction or vacuum is created in simple carburetor at

A. float chamber
B. choke valve section
C. throat section
D. throttle valve section
Answer» D. throttle valve section
398.

The cold start injector provides

A. stoichiometric mixture
B. rich mixture
C. lean mixture
D. heating of fuel
Answer» C. lean mixture
399.

The throttle valve is placed in a draft tube

A. on atmospheric side of the venturi
B. on engine side of the venturi
C. at the venturi
D. none of the above
Answer» C. at the venturi
400.

if the compression ratio of otto cycle is 8.18, what would be the air standard efficiency

A. 0.325
B. 0.658
C. 0.428
D. 0.568
Answer» D. 0.568