Automobile Engineering — Part 1 MCQs with Explanations

Brake fluid is subjected to very high temperatures, especially in the wheel cylinders of drum brakes and disk brake calipers. It must have a high boiling point to avoid vaporizing within the lines. Low viscosity Compatibility with rubber and metal parts

The stroke of an engine is the Distance between T.D.C. and B.D.C.

The seat belt tensioners are built in the Seat belt retractors

The basic part of the engine to which the other engine parts are attached or assembled is the cylinder block An engine block is the structure which contains the cylinders, and other parts, of an internal combustion engine. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attached.

The natural gas is compressed in a CNG cylinder at a pressure of 200bar

Alternators are used in modern automobiles to charge the battery and to power the electrical system when its engine is running.

The crankshaft of a typical inline four cylinder engine has 8 balance weights.

The power source for a brake booster is the pressure difference between the atmospheric pressure and the vacuum pressure in the intake manifold

The path taken by intake air is Air cleaner carburettor (or throttle body) intake manifold intake ports cylinders

The higher the octane number, the more compression the fuel can withstand before detonating . Therefore, high compressibility of the fuel matters mainly for gasoline engines. Use of gasoline with lower octane numbers may lead to the problem of engine knocking

A flywheel is a mechanical device specifically designed to efficiently store rotational energy. Flywheels resist changes in rotational speed by their moment of inertia. The amount of energy stored in a flywheel is proportional to the square of its rotational speed

The compression ratio of a petrol engine is nearly 8 : 1.

Excessive camber angle can lead to increased tire wear and impaired handling. With these control arms installed, tire camber can be effectively changed by simply moving the tires.

In Diesel engines, during suction stroke only air is drawn in the cylinder.

The characteristic that is enhanced by the honing of cylinder sleeves inner surface is Lubrication performance

The valve overlap in four stroke petrol engines is approximately at 30°

In most engines the oil pump is driven by a gear attached to the crankshaft. This is no always a direct drive, sometimes on older engines, the pump was driven by the camshaft gears or even the idler gear.

SAE stands for Society of Automobile Engineers and they standardise a lot of components that are used to build an automobile. From Pipes to electronics to oils. As for SAE 80 is more viscous

SAE20 W50 indicates multi-grade oil

The high temperatures can sheer/crack the oil molecules into smaller molecules, which causes a decrease in viscosity.

The two kinds of piston rings are Compression and oil control rings

The function of a first compression ring is that it Maintains a seal and prevents escape of burned gases and loss of pressure in the combustion chamber

The function of oil control rings is that it Prevents engine oil from going into the combustion chamber and returns excess lubricating oil off the cylinder wall through the return holes in the piston to the oil pan

The sequence order of events in a four stroke engine is Suction compression power exhaust

In a four speed four stroke Diesel engine, the intake valve Opens at 20° before T.D.C. and closes at 35° after B.D.C.

The forced fed lubrication system means that the oil is delivered to the engine by The pressure created by the oil pump

The torque converter uses Automatic transmission fluid (ATF) to transfer torque.

When indicated power (I.P.) and frictional power (F.P.) are known, we can calculate Brake power Friction Power = Indicated power - Brake Power

If the engine coolant leaks into the engine oil, then engine oil Appears milky

The connecting rod lower end is connected to the relevant journal of crankshaft.

In order to implement gear changes in the gear unit of an automatic transmission a Hydraulic multi plate clutch is used.

The engine oil viscosity is defined by Society of automotive engineers (SAE) ratings.

The camshaft of a four stroke Diesel engine running at 1000 rpm will run at 500 rpm

The difference between DOT 3 and DOT 4 brake fluids is DOT 4 fluids have a higher boiling point than DOT 3 fluid

The octane rating of petrol commercially available is 85 - 95

If the spark plug deposit indicates black coating of soot, it indicates that the engine has been generally operating on Too rich mixture

The purpose of a balancer shaft is to Reduce vibrations caused by the crankshaft rotation

A worm gear is used as the pinion for the rack and pinion type of steering gearbox, because it Improves steering comfort when steering wheel is turned to effect small changes in the direction of forward motion

The petrol engines are also known as Spark ignition (S.I.) engines

The Diesel engines are also known as Compression ignition (C.I.) engines