MECHANIC MOTOR VEHICLE
THEORY
SEMESTER – IV JULY 2018
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
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