The aluminium alloy is used in cylinder blocks because
It is lighter and has good heat dissipation characteristics
Material cost is low
It does not require any cylinder liners
The piston is also made of aluminium alloy
Correct Answer :
A. It is lighter and has good heat dissipation characteristics
Related Questions
The major purpose of an electronically controlled automatic transmission is that this type of transmission
Eliminates gear clutches
Eliminates the gear shaft lever
Reduces the number of automatic transmission components
Reduces shift shock and achieves more efficient transmission of engine torque
The function of antilock brake system (ABS) is that is
Reduces the stopping distance
Minimises the brake fade
Maintains directional control during braking by preventing the wheels from locking
Prevents nose dives during braking and thereby postpones locking of the wheels
If clearance volume of I.C. engines is increased, the compression ratio will
Increase
Decrease
Remain constant
Be doubled
Instead of valves, the ports are used in case of
Four stroke I.C. engines
Two stroke I.C. engines
V6 engines
None of these
For the same maximum pressure and temperature
Diesel cycle is more efficient than Otto cycle
Otto cycle is more efficient than Diesel cycle
Both Otto cycle and Diesel cycle are equally efficient
None of the above
The crescent shaped cavity on the piston head top surface is called as
Piston oil hole
Snap ring
Valve recess
Valve clearance
The service brakes employed in cars are generally operated
Mechanically
Hydraulically
Pneumatically
None of these
Two general types of tyres are
Tube type and tubeless
Solid and tubeless
Air and pneumatic
Split rim and drop centre
A petrol engine of a car develops 125 Nm torque at 2700 r.p.m. The car is driven in second gear having gear ratio of 1.75. The final drive ratio is 4.11. If the overall transmission efficiency is 90%, then the torque available at the driving wheels is
8.091 Nm
80.91 Nm
809.1 Nm
8091 Nm
When the brake pedal free play is less than the specified value, then the
Brake drags
Brake fades
Vapour locking occurs in the brake lines
Antilock braking system malfunctions
The problems caused by the wheel imbalance are
Hard steering and hard ride
Poor acceleration and hard steering
Steering wheel vibrations and uneven tyre wear
Poor acceleration and reduced fuel efficiency
The two kinds of piston rings are
Compression and oil control rings
Compression and sliding seal rings
Oil scrapper and oil control rings
Pressure and sealing rings
The heat transfer from coolant to air in the radiator of an automobile engine takes place by
Radiation only
Convention only
Convection and radiation
Conduction, convection and radiation
The condition that results in large quantities of CO emission is
Insufficient air during combustion
Insufficient fuel during combustion
Low temperature combustion
High temperature combustion
The function of a second ring is that it is a
Back up compression ring which will work in place of the top ring when it is broken
Compression ring and aids the top ring in sealing and cooling
Back up oil control ring which will work in place of the bottom ring when it is broken
Cushion ring which prevents piston slap and knock
In Spark Ignition Engine
Only air is introduced into the cylinder
The mixture of air and fuel is introduced into the cylinder from carburettor
Both A and B
None of these
In a Diesel engine, the function of a fuel injector is to
Mix the fuel and air
Ignite the air-fuel mixture
Provide flame front for ignition
Spray atomized fuel in the cylinder
The Diesel engines as compared to petrol engines require
Bigger flywheel
Smaller flywheel
Same size of flywheel
No flywheel
The discharged lead acid battery has on its plates
Lead peroxide (PbO₂)
Spongy lead (Pb)
Lead sulphate (PbSO₄)
Sulphuric acid (H₂SO₄)
The rigid suspension is beneficial when
It is desired to reduce the unsprung mass
It is desired to have more flexibility in design
It is desired to improve tyre to ground contact characteristics
Large changes in load make it necessary to have a large suspension stroke
When turning a corner
The front wheels are toeing out
The front wheels are turning on different angles
The inside front wheels has a greater angle than the outside wheel
All of the above
In a ventilated disc brake
A duct directs air towards the caliper for cooling while the vehicle is moving
Caliper is covered with cooling fins
Disc contains many small holes for optimum cooling performance
Disc contains radial vanes between its rubbing surfaces for optimum cooling performance
In which of the following conditions, the idle CO percentage should be measured with the vehicle?
Headlights and other electrical devices are switched off
Headlights and other electrical devices are switched on
Headlights and other lights are switched off
Headlights are switched on
An underinflated tyre will wear the tread most
Near the centre
Near the edges
In the lateral direction
In the cross direction
The purpose of turning radius gauges is to measure the
Contact areas of the tyres
Free plays of the steering wheel
Turning radius of the left and right wheels
Difference in the toe angles of the left and right wheels
In order to implement gear changes in the gear unit of an automatic transmission, a ________ is used.
Synchronizer
Planetary gear
Magnetic clutch
Hydraulic multi plate clutch
The antiknock property of compression ignition engine fuel can be improved by adding
Tetraethyl lead
Trimethyl pentane
Amyl nitrate
Hexadecane
In a four speed four stroke Diesel engine, the intake valve
Opens at T.D.C. and closes at B.D.C.
Opens at 20° before T.D.C. and closes at 35° after B.D.C.
Opens at 10° after T.D.C. and closes at 20° before B.D.C.
None of the above
A battery can be charged by
Adding distilled water
Adding sulphuric acid
Applying voltage in the reverse direction to that of charging
Applying a voltage in the same direction to that of charging
The motion of the cam is transferred to the valves through
Pistons
Rocker arms
Camshaft pulley
Valve stems