Postby TGTS0907129» Potential difference between two points

Describe the potential difference between two points


The potential difference V between two points is the work done per unit charge when a charge is moved from one point to the other. The defining equations is
V = w/q

Conventionally, q is always understood to be a positive charge thus making definite the algebraic sing of the potential difference in any particular case.

The unit of potential difference in the mks system is the volt. One volt is defined as the potential difference between points in an electric field such that one joule of work must be done to move a charge of one coulomb between the points considered.

Small potential differences are often expressed in mill volts  (1 mV = 10-3 V) or microvolt (1 μV = 10-6V). Large potential difference can be expressed in kilovolts  (1kV = 103 V) or megavolts (1MV = 106 V).

Since the difference of potential between two points is expressed in volts, the potential difference is often referred to as the voltage between these points. Thus, if an electric power line has a voltage of 120 V, it follows that 120 J of work have to be expended for each coulomb of electricity which is transferred through any apparatus connected between the two wires.

By TGTT30071258 on 9/28/2015 12:30:27 AM
TGTS0907129 on 9/28/2015 12:26:17 AM

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