Electric Current in Conductors: Overview, Questions, Preparation

Suppose we take an example of a wire (conductor), through which electric charge flows. Before the passing of electric current through the wire, the electrons move freely and randomly in any direction. As soon as voltage is passed, an electric field is generated. Due to this, the electrons gain a net drift velocity and start moving in a direction opposite to the electric field.

This movement of the charges leads to the generation of an electric current. Usually, metals are preferred as conductors because their electrons can move independently between the atoms of the material.

The flow of electric current can be influenced by the following factors:

Material:

First factor that comes into account is the conductor's material. If the material has a low resistance, it will allow easy passage of electric flow and will be a good conductor of electricity. eg: metals. Similarly, if the material has high resistance, it will oppose the flow of current and will be a bad conductor of electricity. eg: rubber.

Length:

The length of the conductor can also play an important role in the flow of current. Longer the conductor's length, greater resistance will be shown.

Temperature:

if the temperature of the conductor will be high, atoms will have high energies and collide more frequently with each other. This is because of increase in the kinetic energies of the particles.

Candidates who are preparing for JEE MAINS need to be familiar with some important terms related to this chapter:

This is the average velocity of the electrons after passage of electric current.

vd​=I/nAe​

Where,

N = number of free electrons

A = cross sectional area of the conductor

I = electric current

E = 1.6×10^−19 C

According to this law, electric current is directly proportional to the voltage across the conductor.

Mathematical Representation:

V=IR

Where,

V = voltage

I = current

R = resistance

Resistivity

Resistance of a conductor can be given by the general formula:

R=ρ.L​ /A

Where,

Ρ = resistivity

L = length of the conductor

A = cross sectional area of the conductor

Today’s world cannot be imagined without electricity. Each and every area and industry needs electricity for daily functioning. Almost all modern day technologies are possible because of electric current. Here are some useful areas:

• Electrical Appliances 
• Automobile Industry
• Motors
• Generators
• Radios
• Mobile phones and Computers
• Bluetooth and Wifi
• Sensors
• Satellites
• Medical Sector
• Wind Turbines