MECHANICAL ENGINEERING GUIDE ALPHABET WISE

A

Abrasion Test:

It is test for hardness of metal by means of a scratch on the smooth surface of the material being tested.

Abrasive:

Minerals used in different processes like sharpening.

Absorption Dynamometer:

Absorption dynamometer is used for measuring the work done.

Accelerating Pump:

A small cylinder and piston fitted to an SI engine carburetor, and connected to the throttle so as to provide a momentarily enriched mixture when the engine is accelerated. 

Acceleration:

It is the rate of change of velocity. For constant velocity, acceleration is zero.

Accelerator:

Pedal in a motor vehicle which controls the power and speed, by acting on the throttle valve and thereby regulating the mixture of air and petrol entering the engine.

Accelerometer:

Instrument used for measuring acceleration is called accelerometer.

Actinometer:

Instrument for measuring the intensity of the solar rays.

Accumulator:

An Accumulator is an instrument that consists of a heavily weighted tank, which is raised by means of a pump , there by storing up energy to be utilized as required ,by its descent.

Accurate:

Without error within tolerances allowed, precise, correct, confirming exactly to standard.

Acetylene Gas:

When water is poured on calcium carbide, acetylene gas is resulted. Acetylene flame has high illuminating value.

Activity-on-Note (AON) Diagram:

The activity-on-node diagram is an alternative method of representing a project network, in which the jobs or activities are denoted by nodes, while the precedence relationships are represented by the arrows. AON diagram does not require any dummy activities.

Adapter:

Appliance by means of which objects of different sizes will interchange on a spindle or other fitting.

Addendum:

The radial distance between the pitch circle of a gear wheel and the tip of a tooth.

Adiabatic process:

Addiabatic process is one in which there is no flow of heat between a system and its surroundings.

Advance:
In an internal combustion engine cylinder, which the timing of the ignition is altered to cause the spark in the cylinder to pass at an earlier point, there occurs advance.