Let us discuss voltage
This is nature of electric charge to be distributed equally to minimize differences of charges
between two points. How much charge will flow from one point to another point depends on the difference of
charge condition of these two points. This difference of charge condition of two points is called potential difference or voltage
between the points. Let's discuss in detail. Due to the difference of charge condition of two points, there is an electrostatic force
acting between two points. Because of this force, the electric charge migrates from one point to another
As the movable charge migrates in influence of force, we can say there is a work done
or we can say there is a change in potential. How much work is done during movement of charge from one point to another point is expressed
as potential difference or voltage between these two points. This potential difference or voltage is measured with unit of volt
If the voltage between two points is 1 volt, then we can say that the work required during
movement of one Coulomb charge from one point to next point is 1 joule
If the voltage between two points is V volts, Q Coulomb electrical charge has to move from
one point to other. Then work done will be V into Q and say this is W
Therefore V equals to W by Q. In differential form, we can write V equals to dW by dQ
Voltage can be expressed in another way. When a certain charge is transferred from one point to another in a conductor, it will
take certain time. This time depends on the resistance of the conductor
There is a rate at which charge will flow from one point to another
This rate of change flowing in respect of time is called electric current
If resistance is low in the conductor, the current is more. On the other hand, if resistance of the conductor is high, the current through the conductor
is low. This relation is linear. This means current inversely varies with resistance
Now if more voltage is applied across the conductor, there will be more transfer of
charge within same time. That means the rate of change transfer is higher
This relation is also linear. Hence we can say current is directly proportional to the voltage
Combining these two equations and on the basis of Ohm's law, we can write voltage V equals
to current I into resistance R. So voltage across a circuit is the product of resistance of the circuit and current flowing
through it. In case of alternating system, the voltage is defined as the product impedance of the
circuit and the alternating current through the circuit. Hope you got a basic idea of voltage
Thank you