MMV S4

  MECHANIC MOTOR VEHICLE
THEORY
SEMESTER – IV JULY 2018

The combustion in spark ignition engjne.is……..
a. Homogeneous     
b. Heterogeneous   
c. Laminar
d. None of these
Answer: a. Homogeneous     

The degree of turbulence increases…….…with the piston.speed.
a. Indirectly
b. Directly 
c- Linearly
d  None of these
Answer: b. Directly 

Which one of the following is a CFC refrigerant?
a. R 744 
b. R290 
c. R 502
d. R718
Answer: c. R 502

Which motion of follower is best for high spee.d cams?
a. SHM follower motion
b. uniform acceleration and retardatior of foll0wer motion
c. Cycloidal motion follower
d. All of.these                                                                                                                                             Answer: c. Cycloidal motion follower

The purpose of a choke on a carburetor is
a. To provide more air for the engine.
b. To increase the life of the engine
c. To make it run at higher rpm’s
d. To make it easier to crank a cold engine
Answer: d. To make it easier to crank a cold engine

In an electronic fuel injection, the servicing is
a. Difficult
b  EaSy
c. Very Easy                                                                                                                                               d. None of these                                                                                                                                 Answer: a. Difficult

EF1 system can achieve
a. Proper injection timing
b. Proper injection quantity
c. Proper injection pressure                                                                                                                     d. All of these                                                                                                                                           Answer: d. All of these

Petrol or Gasoline is obtained from crude petroleum by means of
a. Distillation
b. Cracking 
c. Both (a) & (b)                                                                                                                                        d. None of these                                                                                                                             Answer: c. Both (a) & (b)
                                                                                                                                                                 Gasoline engines are …………..  than diesel engines.                                                                             a. Heavier                                                                                                                                               b. Lighter                                                                                                                                                 c. Unpredictable                                                                                                                                         d.  None of these                                                                                                                            Answer : b. Lighter

The function of a float chamber in a carburetor is to supply the fuel to the nozzle at a
a. Constant volume head
b. Constant pressure head
c. Variable pressure head                                                                                                                         d. None of these                                                                                                                             Answer : . Constant pressure head

The main metering system of the carburetor consists of
a. The fuel metering orifice through which fuel is drawn from the float chamber
b. The main discharge
c. The passage leading to the idling system
d. All of these
Answer : d. All of these

The functions of the main metering system are
a. To proportion the fuel-air mixture
b. To decrease the pressure at the discharge nozzle exit
c. To limit the air flow at full throttle
d. All of these
Answer : d. All of these

In an electronic fuel injection, the maintenance cost is
a. Low
b. High
c. Normal                                                                                                                                                 d. None of these                                                                                                                             Answer : b. High

The main metering system of the carburetor controls the fuel feed for
a. Cruising
b. Full throttle operations
c.  Both(a)&(b)                                                                                                                                        d. None of these                                                                                                                             Answer : c.  Both(a)&(b)

In electronic fuel injection, there is improvement in the_efficiency due to
comparatively less resistance in the intake manifolds which will cause less pressure losses.
a. Mechanical
b. Volumetric
C. Overall
d. None of these.
Answer : b. Volumetric

Types of Multi-Point Fuel Injection system are
a. Port injection
b. Throttle body injection
c. Both(a)&(b)
d. None of these
Answer :c. Both(a)&(b)


In MPFI-Electronic Control System, the …………….. sensor sends information about the engine speed.
a. Speed
b. Ignition
c. Air-flow
d. Air-mass
Answer : b. Ignition

The following is not an injector fault
a. Nozzle wetness
b. Blue nozzle body
c. Excessive leak off                                                                                                                                  d. Blowholes                                                                                                                                        Answer : d. Blowholes

Commonly used refrigerant in commercial ice plant is
A  C02 
b. Freon 12
c. Ammonia                                                                                                                                                d. Air

Standardization of potentiometer is used for
a. Accuracy
b. Accuracy in measurement
c. Use of low voltage sources                                                                                                                       d. None of these                                                                                                                          Answer : c. Use of low voltage sources

The main aims of an engine management system is to achieve
a. High reliability and durability with lowest possible initial cost
b. High power output and torque
c. Low levels of gaseous and particulate emissions
d. All of these
Answer : d. All of these

A circuit breaker is
a. Power factor correcting device
b. A device to neutralize the effect of transients 
c. A waveform correcting device                                                                                                             d. A current interrupting device.                                                                                                            Answer : d. A current interrupting device.

The following is (are) the part(s) of Electronic Control Unit (ECU)
a. Injector control
b. Spark advance control
c. Idling control                                                                                                                                       d. All of these                                                                                                                                Answer : d. All of these

ECU is an electronic injection system used for
a. Calculating the appropriate injection timing
b. Meeting only certain operating conditions
c. Closing the injection valve only
d. None of these
Answer : a. Calculating the appropriate injection timing

Sensitivity of a sensor can be depicted by
a. Niquist plot
b. Pole- zero plot
c. Bode plot
d.  None of these
Answer : c. Bode plot

Change in output of sensor with change in input is
a. Threashold
b. Slew rate
c. Sensitivity                                                                                                                                              d. None of these                                                                                                                                    Answer : c. Sensitivity

According to Faraday's law, EMF stands for
a. Electromagnetic field c.  Electromagnetic friction
b. Electromagnetic force d.  Electromotive force
c.  Electromagnetic friction                                                                                                                     d.  Electromotive force                                                                                                                       Answer : d.  Electromotive force

For time varying currents, the field or waves will be
a. Electrostatic
b. Magneto static
c. Electromagnetic                                                                                                                                   d. Electrical                                                                                                                                    Answer :

The following affect the voltage required to jump over the gap of spark plug
a. Shape of electrode forming gap
b. The conductivity of gases in the gap
c. Fuel-air mixture ratio existing in the gap
d. All of these
Answer : d. All of these

Following is (are) true for Hall Effect sensors.
a. They can operate as switches of high frequency
b. They cost less than electromechanical switches
c. They are free from contact bounce problem
d. All of these
Answer : d. All of these

During the charging of a lead-acid cell
a. Its voltage increases
b. It gives out energy
c. Its cathode becomes dark chocolate brown in colour
d. Specific gravity of H₂S0₄ decreases
Answer : a. Its voltage increases

The output voltage of a charger is
a. Less than the battery voltage
b. Higher than the battery voltage
c. The same as the battery voltage
d. None of these                                                                                                                             Answer : b. Higher than the battery voltage
The function of duct in air conditioning unit is:
a. Air cooling
b. Air cleaning
c. Air drying                                                                                                                                                       d.  distribution                                                                                                                            Answer : d.  distribution
When speed of an alternator is changed from 3600 r.p.m. to 1800 r.p.m., the generated e.m.f./phases will become
a. One-half
b. Twice
c. Four times                                                                                                                                             d. None of these                                                                                                                             Answer : a. One-half
Alternating current produced by alternator (AC generator) is converted to DC by
a. Stator
b. Brushes
c. Rectifier                                                                                                                                                d. Regulator                                                                                                                                         Answer : c. Rectifier

Which starter does not provide high speed protection to the D.C. shunt motor?
a. Three point starter
b. Four point starter
c. Two point starter                                                                                                                                  d. None of these                                                                                                                                  Answer :

For the protection of D.C. series motor, which starter is commonly used?
a. Two point starter
b. Three point starter
c. Four point starter                                                                                                                                  d. None of these                                                                                                                              Answer :

Radio interference from a fluorescent lamp can be reduced by
a. Putting two lamps in parallel
b. Eliminating choke
c. Putting a capacitor across the lamp                                                                                                     d. None of these                                                                                                                              Answer : c. Putting a capacitor across the lamp

Which of the following is difficult to adopt for dimming?
a. GLS lamps
b. Cold cathode lamps
c. Fluorescent lamps                                                                                                                                   d. All of these                                                                                                                                     Answer : c. Fluorescent lamps

The mirror used for the head light of a car is
a. Spherical concave
b Plane
c. Cylindrical
d. Parabolic Concave                                                                                                                      Answer : d. Parabolic Concave

Nitrogen is added with the argon in an incandescent lamp to
a. Reduce the temperature
b. Reduce the possibility of arcing
c. Increase the brightness                                                                                                                         d. Increase the efficiency                                                                                                                Answer : b. Reduce the possibility of arcing

Latent heat is highest for
a. Refrigerant-22
b. Ammonia 
c. Water                                                                                                                                                   d. None of these                                                                                                                                      Answer : c. Water

Which is the hottest portion of the poppet valve during operation of S.I engine'
a. Valve face
b. Valve head
c. Valve stem                                                                                                                                            d. Valve neck                                                                                                                                   Answer : b. Valve head

Thermostatic expansion valve is used to maintain
a. Constant degree of superheat
b. Constant degree of sub-cooling
c Constant degree of super heat and sub-cooling                                                                                  d.None of these                                                                                                                              Answer : a. Constant degree of superheat

The thermostatic valves opens and provides passage for the flow of water towards the radiator at approximately
a. 90° C 
b. 150° C
c- 250°C
d. 300°C
Answer : a. 90° C 

Inductive proximity sensors can be effective only when the objects are of-materials.
a. Ferromagnetic
b. Diamagnetic
c. Paramagnetic                                                                                                                                       d. All of these                                                                                                                                  Answer : a. Ferromagnetic
Global Positioning System (GPS) is a
a. Satellite Word Station
b. Satellite System
c. Satellite Signal                                                                                                                                      d. Satellite Solution                                                                                                                                  Answer : b. Satellite System

Smallest change which a sensor can detect is
a. Resolution
b. Accuracy
c Precision
d. Scale
Answer : a. Resolution

Choose wrong, size of image formed in a plane mirror
a. Could be taller than mirror
b. Height of image depends on object distance   
c. Width of image is same as of object                                                                                                      d. Image height depends on object height                                                                                      Answer : a. Could be taller than mirror

Following type of sensors are used to generate information in object grasping and obstacle avoidance.
a. Hall Effect sensor
b. Proximity sensor
c. Light sensor                                                                                                                                       
d.  OPtical sensors                                                                                                                           
Answer : b. Proximity sensor
MECHANIC MOTOR VEHICLE    THEORY  SEM - IV JAN2018

l. The thermodynarnic cycle on which the petrol engine works, is
a. Joule cycle
b. Otto cycle
c. Rankine cycle
d. Stirling cycle

In four strokes spark ignition engine, at the end of compression stroke, before the spark occurs, what is the pressure developed inside the combustion chamber?
a. 2 to 4 Kg/cmsq
b. 6 to 8 Kg/cmsq
c. 10 to 12 Kg /cmsq
d. 14 to 16 Kg /cmsq

In a four stroke petrol engine, during suction stroke ....
a. Only air is sucked in
b. Only petrol is sucked in
c. Mixture of petrol and air is sucked in
d. None of these

The sequence of 4 stroke cycle operaåon of S.I. engine is —
a. Induction — power — compression — Exhaust
b. Induction Compression — Power— Exhaust
c. Compression — Induction — Power — Exhaust
d. Compression — Power — Induction - Exhaust

In a two s&oke cycle engine, the four process in a cycle namely suction, compression, power (expansion) and exhaust are completed in revolutions of crank shaft.
a. One b. Two c. Three d. Four

In a single cylinder 4 - stroke S.I engine the power stoke starts after of crank

  a. 90° b. 180° c, 270° d. 360°

Compression Ratio (CR) of Sel engine is less than C.I. engine because .......
a. It makes the engine lighter
b. Less C.R. gives better performance
c. It is a common practice
d. Higher or equal CR is not possible due to the problem of pre-ignition

T - slot provided in the piston .......
a. To accommodate the expansion of piston when heated up
b. For the passage of lubricafrlg oil
c. For cooling purpose
d. To reduce the weight of piston

The part of crank shaft to which connecting rod is connected is called .........
a. Big end
b. Crank pin
c. Crank web
d. Small end

The pefrol engine gets very rich mixture at the time of -
a. Starting
b. Idling
c. Accelerating
d. Operating at cruising speed

ISO - octane content in the fuel of S.L engine .......
a. Retards auto -ignition
b. Accelerates auto - ignition
c. Does not affect auto -ignition
d. None of these

The volumetric efficiency of a good designed engine may be ......
a. 30 to 40%
b. 40 to 60%
c. 60 to 70%
d. 75 to 90%

The venturi in a carburetor causes ......
a. Increase of air velocity
b. Decrease of air velocity
c. Decrease of fuel flow
d. Decrease of manifold vacuum

The main disadvantage of the mechanical fuel pump is that ......
a. They need to be located near the engine
b. They are prone to vapour lock
c. They operate only after the engine has started
d. All of the above

The throttle valve confrols the supply of ........
a. Air only
b. Fuel only
c. Air fuel mixture
d. None of these

The main advantage of electronic fuel injection (EFI) system is ......
a. High quality fuel distribution
b. Less fuel consumption
c. Rapid response of the engine to throttle control
d. All ofthe above

Which of the following component, in EFI system, decides the amount of fuel to be injected on the basis of signals received from the wide range of sensors?
a. ECU
b. Carburettor
c. Throttle
d. Governor

In EFI system the engine temperature sensor senses the temperature of .......
a. Cooling water at out let
b. Cooling water at inlet
c. Suction air
d. Exhaust gas

In EFI system the inlet Manifold Pressure Sensor senses the —
a. Quantity of Air in the inlet manifold
b. Vacuum in the inlet manifold
c. Quantity of fuel supplied in the inlet manifold
d. Any one of the above

In EFI system the exhaust gas sensor senses the percentage in exhaust gas for calculating air-fuel ratio.
a. NOx b. CO c. 02 d. HC

The rate of flow of electrons in a conductor is known as —
a. Current
b. Voltage
c. Resistance
d. None of these

A is an electrical one way check valve that will allow current to flow in one direction   only.
a. Diode
b. Transistor
c. Capacitor
d. Resistor

"Whenever a conductor cuts magnetic flux, an e.m.f. is induced in that conductor." This statement is called as
a. Ohm's law
b. Fleming's rule
c. Faraday' s First law of electromagnetic induction
d. Faraday's second law of elecfromagnetic induction

The Large gap in the spark plug may cause the engine ......
a. Misfiring
b. Over heating
c. Back firing
d. Timing disturbance

The main function of the condenser in an ignition system is .......
a. Minimizing Pitting of the contact breaker points
b. To intensify the spark
c. To absorb the energy stored in the primary winding
d. All ofthe above

In general, the hot plugs haveinsulator nose.
a. Short
b. Thin   
c. Long
d. Thick

The vacuum advance mechanism functions at .......
a. Light engine load
b. Heavy eng;ine load
c. High engine speed
d. None of these

The function of a charging system in an automobile is to
a. Supply elecfric power
b. Convert mechanical energy into electrical energy
c. Continually recharge the battery
d. Partly convert engine power into electric power

The number of diodes used in alternator for rectification from AC to DC is / are ........
a. 1 b. 2 c. 4 d. 6

The charging voltage at the start of the engine is than when the engine is running on load.
a. Higher
b. Lower
c. Equal
d. Any one of these

The high resistance in an alternator output circuit is often caused by .......
a. A bad regulator
b. A shorted diode
c. Loose or corroded connection
d. None of these

The ratio between the number of teeth on the starter motor pinion gear and the engine fly wheel ri.ng gear is about
a. 1:1 b. 1:5 c. 1 : 15 d. I : 100

The magnetic field required for starting motor operation is provided by the .........
a. Armature
b. Field windings
c. Solenoid
d. None of these

If starter motor spins but does not engage flywheel teeth and does not start the engine, the  problem is most likely caused by a bad
a. Magnetic switch
b. Over running clutch
c. Positive battery cable
d. Ignition switch

The colour of tail light in a car is .........
a. White
b. Amber
c. Green
d. Red

The typc of reflector used for automobile head lamp is —
a. Parabolic
b. Hyperbolic
c. Spherical
d. Circular

The stop lights are also known as ..........
a. Tail lights
b. Brake lights
c. Indicator light
d. Fog light

The frequency of flashing light per minute in a turn indicator is about .......
a. 8
b. 80
c. 800
d. None of these

In a horn assembly which of the following part vibrates around 2000 vibrations per second?
a. Diaphragm
b. Tone disc
c. Armature
d. Contact points

A 12 volts windshield wiper motor consumes about .......... ampere of current under normal operation.
 a. 0-1 b. 3-4 c. 10- 15 d. 20 - 30

The purpose of air conditioning a car is to confrol —
a. Temperature and pressure
b. Pressure and humidity
c. Humidity and temperature
d. Temperature, pressure and humidity

Which of the following should be cold during normal operation of the air conditioning  system?
a. Compressor
b. Condenser
c. Receiver and drier
d. Evaporator

Which refrigerant is commonly used in modern automobile air-conditioning system?
a. R- 12
b. R- 22
c. R- 134a
d. R- 134

The purpose of corrugated fins used in condenser and evaporator is to
a. Trap insects and foreign objects, thus preventing them from entering the engine compattment
 b. Control the air flow which passes through the condenser or evaporator
 c. Increase the surface area, thus increasing heat exchange performance
 d. Reinforce the heat exchanger

Which of the following sensor data will the automatic air-conditioning system use to operate the recirculation control motor?
a. Vehicle speed
b. In-car and outside temperatures
c. Engine oil temperature
d. Evaporator temperature

What is/are the causes of wind shield wiper motor running sluggishly?
a. Contact breaker gap is not correct
b. Binding in spindle or gear
c. Excessive blade pressure
d. All of these

What may be the causes if fuel gauge needle always remains at empty?
a. Defective gauge
b. Float arm sticking
c. Float punctured
d. All of these

The important parameter that can be controlled by electronic engine management system are
a. Air fuel ratio
b. Ignition and Injection timings
c. Idle speed
d. All of these

As per service manual recommendations the level of engine oil should be checked when the engine is .......
a. Cold
b. Wormed up
c. Hot
d. Very hot

Which of the following does not come under Vehicle Safety Technology?
a. Air bags
b. Remote key less entry system circuit
c. Tyre pressure monitoring system
d. Night vision Assist

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