The mechanical efficiency (ηm) of an I.C. engine is equal to (where I.P. = Indicated power, B.P. = Brake power and F.P. = Frictional power)
I.P/B.P.
B.P/I.P.
B.P/F.P.
F.P/B.P.
Correct Answer :
B. B.P/I.P.
Related Questions
The purpose of a balancer shaft is to
Balance the timing in the movement of the two groups of pistons
Increase inertia force of the rotating crankshaft
Reduce vibrations caused by the crankshaft rotation
Adjusts the timing of the intake and exhaust valve openings
The most commonly used power plant in automobiles is
Gas turbine
I.C. engine
Battery
None of these
The acid used in automobile battery is
Hydrochloric acid
Hydrofluoric acid
Nitric acid
Sulphuric acid
The specific gravity of acid in a fully charged battery is generally
1.00
1.28
1.82
2.81
Which part of the automobile tyre is subjected to greatest flexing action?
Bead
Side wall
Shoulder
Tread
In a petrol engine, the high voltage for spark plug is in the order of
1000 volts
2000 volts
11 kilovolts
22 kilovolts
The main function of intake manifold is that it
Promotes the mixture of air and fuel
Reduces intake noise
Cools the intake air to a suitable temperature
Distributes intake air equally to the cylinders
The main cause for the change in engine oil viscosity is
Humidity
Temperature
Vibration
Contamination
The specific gravity of petrol is about
0.75
0.85
0.95
1.25
The instrument used to check specific gravity of acid in a battery is
Hydrometer
Hygrometer
Anemometer
Multimeter
The valve tappet clearance is measured by
Screw pitch gauge
Engineering scale
Feeler gauge
Vernier caliper
If a tyre is designated as 175/65 R-14 82-S, then the aspect ratio for the tyre is
175
65
14
82
The most accurate ignition system of a spark ignition engine is
Magneto system
Battery system
Electronic control unit system
Magneto and electronic system
The main function of a resonator is that it
Regulates the intake air flow rate
Reduces the intake air noise
Enhances intake efficiency
Regulates the intake air temperature
The firing order for an opposed four cylinder l.C. engine is
1-2-3-4
1-3-4-2
1-4-3-2
1-3-2-4
The two rows of cylinders in a 'V' type engine are generally arranged at
45°
60°
90°
130°
One effect of detonation is
Delay in ignition
Loss of power
Overheating of engine
Overcooling of engine
The most commonly used supplementary restraint system (SRS) component is
Seat belt
Brake
Airbag
Steering
The main purpose of an engine's air cleaner is that it
Controls the engine's air intake volume
Reduces the engine's air intake noise
Prevents rain water from entering the engine
Prevents dust and other foreign matter from entering the engine
The torque available at the contact between driving wheels and road is known as
Brake effort
Tractive effort
Clutch effort
None of these
The timing belt is attached to the camshaft pulley and
Timing belt drive pulley
Distributor
Radiator fan pulley
Alternator pulley
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
In a four cylinder inline engine, the number of firing strokes in one revolution of the crank is
1
2
3
4
Two speed reverse gear arrangements is generally provided in case of
Passenger cars
Matadors
Tractors
Trucks
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 battery is an electrochemical device, which means battery
Makes chemicals by mechanical means
Uses chemical action to provide electricity
Has curved plates instead of flat plates
Does not use an electrolyte
The process of supplying the intake air to the engine cylinder at a pressure greater than the pressure of the surrounding atmosphere is known as
Supercharging
Auto ignition
Scavenging
Detonation
In bias ply tyres
All plies run parallel to one another
Belts of steel mesh are used in the tyres
One ply layer runs diagonally one way and another layer runs diagonally the other way
All of the above
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
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