1. Define limit, and fit?

Fit is defined as the degree of tightness and looseness between two meeting part

 

  1. What is the working principle of hydrostatic propulsion system in a tractor?

It depends on pascal law. As the pressure in the system is the same, the force that the fluid gives to the surroundings is therefore equal to pressure x area. In such a way, a small piston feels a small force and a large piston feels a large force

 

  1. WHY THE COLOR OF VEHICLE TYRES ARE ALWAYS BLACK IN COLOUR.

IS THERE ANY THING RELATED WITH HEAT CONDUCTION?

During the process of vulcanization of rubber to make it sheer resistant to make tyres out of it, a certain proportion of carbon is mixed into it. Without this procedure the tyres will not be able to withstand the friction n stress of the road. This carbon is responsible for giving tyres the characteristic black color. When ozone combines with ultraviolet light from the sun, it attacks the tire polymer. To prevent tires from rapidly deteriorating, a sacrificial absorber is used, “carbon black” – which, fittingly, makes tires black

 

  1. What is staring oil grade SAE no’s of gear box, in passenger car?

“SAE” STAND “SOCIETY OF AUTOMOTIVE ENGINEERS” (USA).

SAE20W40:4WHEELER ENGINE, 2 WHEELER ENGINE, GEAR BOX &CLUTCH.

SAE40W60: GEAR BOX OF RWD & 4WD VEHICLE.

 

  1. WHAT IS TRANSVERSE WEIGHT SHIFT DUE TO DRIVE TORQUE?

It is weight of drive torque which is bolted to chassis of the car.

 

  1. Why tractor rear wheel is big then front wheel?

For maximum torque provide

 

  1. What is the range of the engine efficiency for two stroke engine? Why you don’t see two stroke engine in car? What are problem with two stroke engine?

 

The range of two stroke engine is too high compare to the four stroke engine because of each revaluation one power in two stroke engine. I cannot see the 2 stroke engine in car. Power loss is more.

 

  1. What is an injector pressure in heavy vehicle?

Injector pressure is 220 kg/cm square

 

  1. WHAT IS THE MEANING OF CC OF ENGINE?

CC stands for Cubic centimeter. CC represents the total volume of an engine cylinder. The engine which has more CC, can produce more power than others.

 

  1. WHAT IS THE DIFFRENCE BITWEEN BS2 & BS3 ENGINE?

IN BS2 there is No catalytic converter to reduce formation of co and HC whereas in BS3 catalytic converter is available to reduce the formation of HC and CO. So less emission of HC and co will take place in BS3

 

  1. What is BHP & How it is measured?

BHP stands for Brake horse power. As the name implies it is the braking power required to stall an engine Means horse power required to stop engine rotation

 

  1. By mixing oil in fuel of four stroke bike will it damage engine, performance? If not than what happen?

Yes, absolutely. It leads to higher wear and tear in cylinder liners, piston and damage of the piston. It even leads to knocking and detonation where abnormal combustion appears and dark smoke and harsh sound will be produced by the engine.

 

  1. Does the design & fittings vary on the type of the vehicle engine? Why they use petrol for engines only & vice versa?

No, the type of fitting & design does not vary for automotive segment. It’s the same. However, it’s different in case of aerospace & other sector. In the fittings, usually of hole/shaft one of those is made at the basic size so that it can accommodate the other one.

 

  1. For the purpose of inflating car tires, spray painting, etc. i.e. say a small workshop, what size of a compressor (CFM) is recommended? It will be generally for a hobby use and not commercial use?

Spray painting it is generally used for painting in a very smaller areas of any part and where it is very hard to paint in a brush…. And to improve faster rate of painting, Spray painting r used……..usually reciprocating compressor r used but size depends upon requirement………..

 

  1. Explain different between two stroke engine four stroke engines?

In a two stroke engine, for every two rotations of the crank shaft there will be one power stroke. Hence during compression stroke, fuel will be drawn in to the crank case (suction) and during power stroke, burnt fuel will be thrown out through transfer ports (exhaust). In a four stroke engine, for every four rotations of the crank shaft there will be one power stroke. Here, suction, compression, power & exhaust strokes are separate as there will be inlet and exhaust valves.

 

  1. What is the formula for calculating BHP IN SI UNITS?

Boiler horse power (BHP) is a power unit used for measuring the power output of boilers, widely used in the past, but now confined to North America. The boiler horsepower conversion formula is as follows.

1 Boiler Horsepower = 9,809.5 Watts

 

  1. WHAT IS KING PIN OFFSET?

A geometric parameter which is positive if the kingpin axis intersects the wheel plane at or below ground level, or is negative if the point of intersection is above ground level. Also called scrub radius

 

  1. WHY BIG TYRE USED IN REAR OF VEH?

Tractors have big rear tires because, the larger the surface area of the tractor’s wheels touching the ground, the more pulling power you have. Like how tractor pullers have large tires.

Another reason is that the tractor doesn’t have to operate at a higher speed to get the same ground speed with larger tires. Gear ratios don’t have to be as high b/c of the larger tires.

By bpci