(2) It is possible to pile up electrons at one point and remove them from the
other point by means of a battery or generator. The greater the excess of electrons at
one point and deficiency of electrons at another, the greater is the attraction or
difference in potential between these points.
(3) The unit of measurement of this potential difference is the volt. A volt is
the amount EMF needed to drive a current of one ampere through a resistance of one
ohm.
b. Current.
(1) The intensity of electric current is determined by the number of electrons
flowing past a point. in one second. The greater the number of electrons flowing per
second, the greater the value of the current.
(2) The unit of measurement of current strength is the ampere, which is one
coulomb of electricity flowing per second. The unit of quantity of electricity is a
coulomb, which is 6.28 x 1018 electrons. The milliampere (mA) is 1/1000 as large as the
ampere. Thus 6.28 x 1015 electrons (0.001 coulomb) flowing per second is equal to one
mA.
NOTE:
The mathematical shorthand used above is the explained as follows:
101 = 10
105 = 100,000
102 = 100
106 = 1,000,000
103 = 1,000
1012 = 1,000,000,000,000
104 = 10,000
1015 = 1,000,000,000,000,000
Thus, the power to which 10 is raised is equal to the number of zeroes in the fully
c. Resistance.
(1) In an electric circuit, resistance depends on the type and physical
dimensions of the material making up the circuit. Every conductor resists the flow of
electrons through it. Opposition or hindrance to the flow of electrons in an electric
circuit is called resistance.
(2) The unit measure of resistance is the ohm; it is symbolized by the Greek
letter omega (Ω)
MD0950
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