If atomic power replaces the present sources of power, we shall get more power than we produce The higher the temperature of a metal, the higher is its resistance. Besides, could we use a silver wire, it would offer less resistance than an iron one. In short, the thinner or longer the wire, the greater is the offered resistance. Among them we find its size, length, type and temperature. One should mention in this connection that certain factors can greatly influence the resistance of an electric circuit. The potential difference becoming great enough, the electrons will jump through the air forming an electric spark. All that we have to do, is to increase the charges. As a matter of fact, it is not necessary at all to connect both balls in the manner described in order to obtain similar result. However, the electrons could certainly flow from the negatively charged ball towards the positively charged one, provided we connected them by a metal wire. How can we explain this strange behaviour? The simple reason is that the air between the balls offers too great a resistance to current flow. In spite of our having a difference" of potential, no current flows. 9 two oppositely charged balls are suspended far apart in the air.
forget, too, that all substances do allow the passage of some current, provided the potential difference is high enough.
Take glass and rubber as an example! They offer a very high resistance and, hence, are considered to be good insulators. This resistance may be high or low depending on the type of circuit and the material employed. The reader most probably remembers that all substances offer a certain amount of opposition, that is to say resistance, to the passage of current. So, to resistance shall we turn our attention now. In addition to electromotive force and potential difference Terence should be made here to another important factor that greatly influences electrical flow, namely, resistance. The source under consideration may be a cell, a battery, a generator, a thermocouple or a photo cell, с Needless to say, the emf is measurable and it is the volt that is the unit to be used for measuring it. One need not explain to the reader that a current is unable flow in a circuit consisting of metallic wires without a source of emf. On the other hand, were the electromotive force alternating, the current would be alternating, too. In case this emf is direct, the current, too, is direct. In effect, it is the emf that moves electrical charges from one point in an electric circuit towards another. The electromotive force is the very force that makes the electrons move along a conductor, the letters emf standing for the above term. Unless there were a flow of electric current between A and В in any direction, it would mean that both the former and the latter were at the same potential. Let us suppose that there is a movement of electrons through the wire, say, from point A to point B! What does it mean? It means that there is an excess of electrons at point A. Of course, the greater the difference, the greater is the flow.
WHERE IS THE OUTLINE TEXT EFFECT IN WORD 2013 FREE
It is the difference of potential that causes the free electrons to flow from one point of the conductor to another. Thus, if at one end of a conductor there is an excess of electrons and at the other end-a deficiency, the excess of electrons will flow in a disorderly manner towards the point of deficiency. As was previously stated, there is always a disorderly movement of free electrons within all substances, especially metals. The amount of electrons at a point is known as the potential at that point. POTENTIAL DIFFERENCE, ELECTROMOTIVE FORCE AND RESISTANCE
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