What is electricity in physics?

The first thing which comes to our mind in the study of electricity is the generation of electric current, which we shall show as the rate of motion of charges in a conductor.

The best conductors are metals, particularly silver, copper, gold, aluminium. In these metals, the electric charges can flow very easily.

In metallic conductors, there is always present a large number of free electrons actually detached from their parent atoms which constitute a kind of electron gas. These free electrons are capable of moving freely in random directions in the inter atomic space of the metal.
In insulators, the electrons are rigidly bound to the atoms and so cannot move and hence no current can flow through them.
In the absence of an electric field across the conductor, the free electrons have a thermal velocity at normal temperature which is of the order of a million meter per second.

The velocities of these electrons are randomly directed and in effect the number of electrons moving in the opposite direction to maintain the neutral state of on establishing an electric field between the two ends of a wire by applying a potential difference, these free electrons having a negative charge on them, experience a force in the opposite direction to the field and hence acquire an acceleration in that direction. These free which, in the absence of the electric field were moving towards the positive terminal of the battery are now accelerated while those moving away from the said terminal are retarded, the net effect is that an additional component of velocity towards the positive terminal is superimposed on the free electrons over their thermal velocity after they suffered certain number of collisions with the atoms.
This additional component of velocity due to the electric field is known as drift velocity. The magnitude of this velocity is of the order of 0.01 metre per second.
This drift velocity in the free electrons is really responsible for the generation of electric current in the wire. Thus we see that electric current in a conductor is due to the flow of electrons.
From differnet equations by putting the given values of 'm' in the given equation y=mx.
For each equation work out corresponding value of dependant variable 'y' by putting different values of independent variable 'x'.
Take at least five observations by changing the independent variable in regular steps over a suitable and wide range.
Draw two mutually perpendicular lines as reference axes.
One horizontal coinciding with the thick horizontal line of the graph paper and near the botttom of the graph paper to represent x-axis and the other vertical along the extreme left of the graph paper to represent y-axis.