If clearance volume of I.C. engines is increased, the compression ratio will
Increase
Decrease
Remain constant
Be doubled
Correct Answer :
B. Decrease
Related Questions
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
In Diesel engines, the duration between the time of injection and the time of ignition is called
Spill cut-off
Delay period
Injection period
Ignition period
The natural gas is compressed in a CNG cylinder at a pressure of
200 bar
220 bar
250 bar
300 bar
The component of the oil filter that prevents the passage of metal particles and sludge is
Element
Relief valve
Check valve
Case
The purpose of transmission in an automobile is
To vary the speed of automobile
To vary the torque at the wheels
To vary the power of automobile
None of these
The order in which effort applied to the steering wheel is transferred to the front wheel is
Steering wheel, steering gearbox, steering shaft, tie rod, steering knuckle, front wheels
Steering wheel, steering shaft, steering gearbox, tie rod, steering knuckle, front wheels
Steering wheel, steering shaft, steering gearbox, steering knuckle, tie rod, front wheels
Steering wheel, tie rod, steering gearbox, steering shaft, steering knuckle, front wheels
Which of the following indicates multigrade oil?
SAE 30
API SF
SAE 20 W50
API 50
The component that connects the steering rack to the knuckles is
Tie rod
Sector gear
Pivot
Spline
The main feature of Macpherson strut suspension is that
The vertical size of the suspension can be made more compact
Non vertical external forces are supported by the suspension arms
The unsprung mass in lighter
The assembly is slightly more complicated in design
The fuel pump of a programmed fuel injection (PFI) system operate for two seconds when the ignition is turned to the start position to
Enable the pump's fault diagnosis function to operate
Warm up and lubricate the pump
Supplies a large amount of fuel and thereby creates a choke effect
Pressurise the fuel system before the engine is started
If the spark plug deposit indicates black coating of soot, it indicates that the engine has been generally operating on
Too lean mixture
Stoichiometric mixture
Most economical mixture
Too rich mixture
The formula for Isooctane is
C8H18
C7H17
C6H18
C7H18
The advantage of having a tandem master cylinder arrangement in automobiles is that it
Enhances safety by serving two independent lines in a divided line brake circuit
Enhances safety by activating the brakes using vacuum pressure in the event of brake fluid loss
Supplies equal fluid pressure to each line of a divided line brake circuit, thereby preventing the brakes from dragging on one side
Boosts the brake fluid pressure to reduce the force required to depress the brake pedal
If the air-fuel mixture in a spark ignition engine is too rich, then airfuel ratio is about
17 : 1
15 : 1
13 : 1
10 : 1
The stroke of an engine is the
Volume of the cylinder
Length of the connecting rod
Internal diameter of the cylinder
Distance between T.D.C. and B.D.C.
In a Diesel engine, the fuel is ignited by
An electric spark
The heat of compression
The hot exhaust
None of these
The main task of a battery in automobiles is to
Supply electricity to the alternator
Act as a reservoir or stabilizer of electricity
Supply electricity to the vehicle's electrical system at all times while the engine is running
Supply a large amount of power to turn the starter motor when the engine is being started
The compression ratio for Diesel engines usually lies in the range of
6-10
10-1
15-25
25-40
The cetane rating of Diesel fuel is in the order of
25
45
70
90
Which of the following is not a part of the chassis?
Wheels
Front axle
Steering system
Seats
When the battery is half (50%) charged, the specific gravity of acid in a battery is usually
0.74
1.00
1.12
1.19
The main function of a master cylinder is to
Adjust the extent of brake pedal free play
Boost the force applied to brake pedal
Convert brake pedal force into hydraulic pressure
Ensure that all the wheel brakes are supplied with the same amount of fluid pressure
The air gap between the central electrode and ground (or side) electrode of a spark plug is around
0.2 mm
0.5 mm
1 mm
1.5 mm
The discharged lead acid battery has on its plates
Lead peroxide (PbO₂)
Spongy lead (Pb)
Lead sulphate (PbSO₄)
Sulphuric acid (H₂SO₄)
The function of an oil control orifice is that it
Returns cylinder head lubricating oil to the oil pan at high speed
Turns oil into fine mist for spray lubrication
Regulates the pressure of engine oil supplied by the oil pump for the lubrication of cylinder head mechanism and other purposes
Removes impurities from cylinder head lubricating oil
The frequency of flashing of light per minute in a direction (side turn) indicator is about
9
90
900
9000
The parking brakes employed in vehicles are operated
Mechanically
Hydraulically
Pneumatically
None of these
In a four wheel drive (4WD), the numbers of gear boxes are
1
2
3
4
In automobiles G.V.W. refers to
Gross vehicle width
Gross vehicle weight
Gross vehicle wheel base
Gross vehicle wheel track
The air resistance to a car at 20 kmph is R. The air resistance at 40 kmph will be
R
2 R
4R
4 R²