1. What is kingpin offset? State some of its application.

Answer:

The kingpin offset is the part, basically called as pivot used in the steering of the vehicles. This offset helps in rotating of the steering and thus it’s very useful in steering mechanism of the cars. Applications: This is also used to measure scrub radius with the help of geometric parameters of wheel plane above and below ground level. It provides directional stability to the vehicles when it i combined with the caster.

2. Explain the basic difference between BS2 and BS3 engine

. Answer:

The basic difference of BS2 and BS3 engines is the presence of catalytic converter. Catalytic converter is present in BS3 engine which helps in reducing the formation of HC and CO. While in BS2 engine, no catalytic converter is present which forms HC and CO. Thus in BS3 engine there is no emission of harmful CO and HC. The full form of BS is bharat stage, which is a standard of emission in India.

3. In a tractor, how the hydrostatic propulsion systems work?

Answer:

This system is based on Pascal’s law. In a tractor the pressure is same, so the force given by the liquid to the surrounding is equal to the pressure × area. Thus, obeying the Pascal’s law hydrostatic propulsion system is designed, similarly small piston feels small force and the large piston feels larger area.

4. Explain the reason that why the tyres are always black in color. Is this phenomena related to the heat conduction?

Answer:

Tyres color is black due to the proportion of carbon mixed in it during the vulcanization of the rubber, to make the tyre shear resistant. Without vulcanization tyres won\'t be able to bear the friction heat and stress of the road. Thus carbon is responsible for giving tyres the prominent black color. Adding of carbon prevents tyres from rapidly deteriorating because when ozone combines with the ultraviolet light from the sun. It attacks the polymer of the tyre.

5. What is back compressor in engines?

Answer:

Back compression means the compression capability of the engine. A diesel engine can compress at the ratio of 14:1 to as high as 25:1. Thus the higher compression leads to better efficiency of the engine. Thick black smoke is emitted when the engine’s compression is reduced which leads to the deformed head-gasket lead into crankcase.

6. Why the plastic materials used in the screwdriver\'s handles?

Answer:

Due to non-conducting nature of plastic, it is widely used for the electricity purposes. Moreover, plastic is cheap and strong so it is less prone to damage. Furthermore, plastic does not bend and does not slip from the users hands.

7. Does diesel engine powered automobile use unit pump and unit injector?

Answer:

In the case of the engines powered by diesel fuel supply systems, unit pump & unit injector are operated by camshaft & thus pressure of injected fuel depends on engine speed. Whereas, in common rail systems it is independent of engine speed.

8. What are MPFI and TPFC systems?

Answer:

MPFI stands for Multi Point Fuel Injection. In this system fuel is injected into the intake ports which is situated just upstream of each cylinder’s intake valve. These systems are sequential systems, in which injection is timed to coincide with intake stroke of each cylinder. TPFC stands for transient power fuel control system. In this type of systems constant choke carburettor is used. The salient feature of this carburettor is that it provides jerk less engine raise. In these systems, throttle valve creates vacuum which opens the slide which controls the air fuel ratio through a tapered jet.

9. Why does a compression engine use high octane fuel?

Answer:

The property of a fuel, which describes how fuel will or will not self-ignite, is called the octane number or just octane. Engines with low compression ratios can use fuels with lower octane number, but high compression engines must use high-octane fuels to avoid self-ignition and knock.

10. What is pitching in the suspension system?

Answer:

Pitching is a rocking action about a transverse axis through the vehicle, parallel to the ground. The front suspension moves out of phase with the rear, experiencing the rocking effect due to pitching. What do you mean by Independent suspension? Independent suspension refers to the mounting of the wheel on a separate axle, so that road shocks affect only the particular wheel.