Amperage (Current) And Voltage.

Basic Electronics
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current of electricity (approximately what a 100-watt light bulb would

draw), it actually involves a tremendous flow of electrons. More than six

billion electrons a second are required to make up one ampere.

(2) Voltage.

Electrons are caused to flow by a difference in

electron balance in a circuit; that is, when there are more electrons in one

part of a circuit than in another, the electrons will move to where they are

lacking.

This difference in electron concentration is called potential

difference or voltage (E). The higher the voltage, the greater the electron

imbalance becomes. The greater this electron imbalance, the harder the push

on the electrons (more electrons repelling each other) and the greater the

current of electrons in the circuit.

When there are many electrons

concentrated at the negative terminal of a generator (with a corresponding

lack of electrons at the positive terminal), there is a strong repelling

force on the electrons moving in the wire.

This is exactly the same as

saying that the higher the voltage, the more electric current will flow in a

circuit; all other things, such as resistance, being equal.

b. Resistance. Even though a copper wire will conduct electricity with

relative ease, it still offers resistance to electron flow. This resistance

(R) is caused by the energy necessary to break the outer shell of electrons

free, and the collisions between the atoms of the conductor and the free

electrons.

It takes force (or voltage) to overcome the resistance

encountered by the flowing electrons. This resistance is expressed in units

called Ohms. The resistance of a conductor varies with its length, cross-

sectional area, composition, and temperature.

A long wire offers more resistance than a short wire of the same cross-

sectional area. The electrons have farther to travel.