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.