# Batterr and the basics of charge flow

## HOW DO YOU FIND THIS

Poll closed Jun 9, 2005.

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1. Jun 6, 2005

### crimsonflames

dear ppl,

i have a basic conceptual doubt about the flow of charge in batteries and the difference between e.m.f and the potential difference.
if you visit the site

http://www.glenbrook.k12.il.us/gbssci/phys/Class/circuits/u9l1a.html [Broken]

everyhting goes well till the third page where the following paragraph:

It is often convenient to speak of an electric circuit such as the simple circuit discussed here as having two parts - an internal circuit and an external circuit. The internal circuit is the part of the circuit where energy is being supplied to the charge. For the simple battery-powered circuit which we have been referring to, the portion of the circuit containing battery is the internal circuit. The external circuit is the part of the circuit where charge is moving outside the battery through the wires on its path from the high potential terminal to the low potential terminal. The movement of charge through the internal circuit requires energy since it is an uphill movement in a direction that is against the electric field. The movement of charge through the external circuit is natural since it is a movement in the direction of the electric field. When at the positive terminal of the battery, a positive test charge is at a high electric pressure in the same manner that water at a water park is at a high water pressure after being pumped to the top of a water slide. Being under high electric pressure, a positive test charge spontaneously and naturally moves through the external circuit to the low pressure, low potential location.

As a positive test charge moves through the external circuit, it encounters a variety of types of circuit elements. Each circuit element serves as an energy-transforming device. Light bulbs, motors, and heating elements (such as in toasters and hair dryers) are examples of energy-transforming devices. In each of these devices, the electrical potential energy of the charge is transformed into other useful (and non-useful) forms. For instance, in a light bulb, the electric potential energy of the charge is transformed into light energy ( a useful form) and thermal energy (a non-useful form). The moving charge is doing work upon the light bulb to produce two different forms of energy. By doing so, the moving charge is losing its electric potential energy. Upon leaving the circuit element, the charge is less energized. The location just prior to entering the light bulb (or any circuit element) is a high electric potential location; and the location just after leaving the light bulb (or any circuit element) is a low electric potential location. Referring to the diagram above, locations A and B are high potential locations and locations C and D are low potential locations. The loss in electric potential while passing through a circuit element is often referred to as a voltage drop. By the time that the positive test charge has returned to the negative terminal, it is at 0 volts and is ready to be reenergized and pumped back up to the high voltage, positive terminal.

makes absolutely no sense,,

since it is in complete contradiction with what has been explained in the earlier two pages and even this page till this point.

so could someone tell me how actually EVERYTHIG IS HAPPENEIN" INCLUDING INTERNAL ,, EXTERNAL CIRCUITS,, ELECTRIC FIELDS ,, ELECTROSTATIC FORCE,, NON-ELECTROSTATIC FORCE,, E.M.F AND POTENTIAL DIFFERENCE ,, AND FINNALY WHERE WHICH CHARGE FLOWS??? :yuck: :yuck: :yuck:

THANKS AND BYE

Last edited by a moderator: May 2, 2017