HOW ELECTRICITY FLOWS. LINES OF FORCE

№ 17. HOW ELECTRICITY FLOWS

Electrons are minute negative charges of electricity. As these minute charges move along a wire, that wire carries an electric current. In other words, an electric current is the flow of electrons through a metal conductor. The electric current flows from the positive to the negative terminal though the electrons really move from minus to plus. In order to have a steadily current, we must have a completed circuit that is also called "closed circuit" and a continuous supply of electric charge. The electric current flows if there is a completed circuit. Thus, current starts flowing at the very moment when we close the circuit, for instance, as soon as we turn on the light in our room. There is no flow of electrons along the conductor and therefore no light as soon as we switch off, break the electric circuit.

№ 18. LINES OF FORCE

Faraday represented the electric field around an electrically charged body by means of lines which he called lines of force or lines of electric intensity. A positive unit of electric charge will tend to move along a line of force in the direction of the electric intensity, and a negative unit of charge tends to move in the opposite direction. It is obvious that two lines of force can never meet. At any rate, one should always remember that lines of force do not really exist and that they by no means indicate a structure of the medium. We use these lines of force, as did Faraday, in order to picture the electric field more clearly. Representing the electric field by means of these lines helps us in picturing the forces existing between the charged bodies.

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