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current will be in amperes. This can be stated more simply in equation form--

(1)	I = E/R	where	I is the current in amperes
			E is the e.m.f. in volts
			R is the resistance in ohms
		The symbol "=" always means "equals."
		The symbol / between E and R means that E is divided by R.

    There is, therefore, something in addition to the e.m.f. (pressure) that determines the amount of the current that will flow. This something is the resistance of the wires making up the circuit and other devices used in the electric circuit. The greater the resistance, the less the current (keeping the voltage unchanged). When a resistance device of any kind is placed in a series circuit, the current is forced through it, and heat is produced by the friction between the moving electrons and the obstructing material of the conductor. That is exactly what
Fig. 2
    happens in the case of the flash light bulb, and enough heat is produced to make the resistance wire "white hot." And because this white hot wire is in a vacuum, it glows brightly without burning up, and we have a light. Accordingly, we can make the general statement that a flow of current in a resistance always results in heat.
    Returning to Fig. 1(b) , let us assume that the resistance is 5w (the Greek letter w "omega" is universally used by Radio men to represent "ohms" and is placed to the right, above the number; 5w would be read 5 ohms). The e.m.f. produced by a dry cell is known to be 1.5v or one and a half volts ("v", symbol for volts). What current will flow?
    From equation (1): I equals E divided by R. Substituting the known values for E and R, we find that I equals 1.5 volts divided by 5 ohms which gives us .3 or 3/10 of an ampere.

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Webpage	©1997, Nostalgia Air
Transcriber	Jennifer Ellis