The purpose of a thermostat in an engine cooling system is to
Prevent the coolant from boiling
Allow the engine to warm up quickly
Indicate the coolant temperature
Pressurise the system to raise the boiling point
Correct Answer :
B. Allow the engine to warm up quickly
Related Questions
The gradient resistance to a vehicle having a mass of 980 kg moving on an incline of 10° is
1.6694 N
16.694 N
166.94 N
1669.4 N
In a square type engine
Geometrical shape is square
Diameter and length of piston are same
Two cylinders are placed horizontal and two vertical
Stroke length and cylinder bore are same
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
The function of a proportioning control valve (PCV) in a brake system is to
Ensure that equal pressure is supplied to the front and rear brakes throughout every braking operation
Reduce the brake fluid pressure when the brakes approach their lockup point
Cause less brake fluid pressure to act on the front brakes than on the rear brakes when the fluid pressure exceeds a predetermined level
Cause less brake fluid pressure to act on the rear brakes than on the front brakes when the fluid pressure exceeds a predetermined level.
The clutch is located between the transmission and the
Engine
Rear axle
Propeller shaft
Differential
The firing order for an inline four cylinder I.C. engine is
1-2-3-4
1-3-4-2
1-2-4-3
1-3-2-4
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
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
The valve overlap in four stroke petrol engines is approximately
30°
60°
90°
120°
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
The size of engine cylinder is referred in terms of its
Diameter and bore
Displacement and efficiency
Bore and stroke
Bore and length
The fuel that detonates easily, is
N-heptane
Iso-octane
Benzene
Alcohol
The main characteristics of a maintenance free (MF) battery is that
A maintenance free battery requires little maintenance during normal use and it is sufficient to add water instead of an electrolyte containing sulphuric acid
A maintenance free battery has a relatively short shelf life when compared with standard batteries
Since it is sealed, the water in maintenance free battery is not lost through evaporation thus accordingly it is not necessary to top up the cells with water
Recharging of a maintenance free battery is neither required nor possible
A clutch is usually designed to transmit maximum torque which is
Equal to the maximum engine torque
80 % of the maximum engine torque
150 % of the maximum engine torque
None of these
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
A four cylinder engine has a capacity of 2.4 litres. The swept volume of one cylinder is
400 cm³
600 cm³
1200 cm³
2400 cm³
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 frequency of flashing of light per minute in a direction (side turn) indicator is about
9
90
900
9000
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
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 reconditioning process used to give cylinder bore surfaces a crosshatch pattern, is known as
Honing
Porous plating
Boring
Shot peening
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
In a four wheel drive (4WD), the numbers of gear boxes are
1
2
3
4
The main function of the tread pattern on tyre is that
The tread grooves pass air between the tyre and road surface, thereby preventing tyre from overheating
The crests between the tread grooves absorb road noise
In wet conditions, the tread grooves expel water that is drawn between the tyre and road surface
The tread pattern protects the tyre's inner carcass from small stones and pieces of glass
Thinner is added to the paint in order to
Make pigments and resin mix easily
Make paint film hard
Optimise its viscosity
None of these
A heat treated glass generally used in automobiles bursts into ________ upon cracking,
Sharp edged fragments
Small particles
Large particles
None of these
The rolling resistance is because of the friction between the
Wheel rim and tyre
Tyre and the road surface
Wheel rim and road surface
None of these
An engine has a clearance volume of 100 cm³ and a swept volume of 800 cm³. The compression ratio is
7 : 1
8 : 1
9 : 1
10 : 1
When indicated power (I.P.) and frictional power (F.P.) are known, we can calculate
Brake power
Compression ratio
Specific air consumption
Mean effective pressure
The difference between DOT 3 and DOT 4 brake fluids is
DOT 4 fluids have a higher boiling point than DOT 3 fluid
DOT 4 fluids have a lower boiling point than DOT 3 fluid
DOT 3 and DOT 4 fluids have the same boiling point, but DOT 4 fluid has a longer service life
DOT 4 fluid is more resistant to freezing than DOT 3 fluid