Introduction to potential difference

The bliss of breeze

While we walk along the sea shore we experience the bliss of breeze

These breeze take place due to the difference of temperatures between sea and land

Wind blows from the region of low temperature to the region of high temperature

It moves due to the difference in the air pressures

Similarly water in our houses flows from high to low pressure

Water does not flow in the perfectly horizontal tube from one point to another

In our houses one end is connected to a tank kept at a higher level and taps are at a lower level

This leads to pressure difference between two ends of the pipe

As a result, water flows from the tank at higher level to the taps at lower level

Similarly, charges do not flow by themselves. There is some property which results in the movement of charges

Just like pressure difference in case of water flow, charge flow takes place due to certain property

This property is the electric potential difference, which causes charge flow

Potential difference

Charges flow due to potential difference from higher potential to lower potential

The charges flow from the abundant region to deficient region

And this flow of charges is known as the electric current

For convention the current flows in direction of flow of positive charge

Hence it opposite to that of the motion of negative charge i.e. electrons

The flow of current in wires takes place due to the difference of potential

To know about potential difference, we must be aware of the term potential

Potential of a point is the work done to bring a unit charge from infinity to that point

And the electric current flows due to the difference of this potential, from higher to lower potential

The same has been verified by experiment

In experiment we connect two spheres

We observe flow of electrons from negatively charged sphere to neutral sphere

Electrons flow until the potential difference becomes zero

So, for further experiment we replace negative charge by positive charge

Flow of electrons is from neutral sphere to positively charged sphere

And to study this thing more deeper, we connect both positive and negative spheres

Flow of electrons is from negatively charged to positively charged sphere

It proves that current flows from higher to lower potential


The current flow takes place in conductors because of the potential difference

Conventionally, the direction of current is opposite to the direction of flow of electrons

Electric potential of a point is work done to bring unit charge from infinity to that point against electrostatic force

The End