## மாணவர்களே வினாக்கள் வீடியோ வடிவில் உங்களுக்காக கிளிக் செய்யுங்கள் லிங்கை

மாணவர்களே வினாக்கள் வீடியோ வடிவில் உங்களுக்காக கிளிக் செய்யுங்கள் லிங்கை

### MECHANIC MOTOR VEHICLE THEORY SEM - IV JAN2018

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 .......
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 .......
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
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
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