# Cause of resistance

Resistance is a property of  a material by which it opposes the flow of electric charges through it. Resistance are mostly used in electronics and electrical circuit to limit the current.There are many types of resistors are used in circuit such as metal film,wire wound,thick film etc.

In this article we will discuss about the cause of resistance which means that how a material offers opposition to the electric charge. So let us discuss this  below.

Cause of  Resistance

Every material is made up of small atoms and atoms contain electron,proton and neutron. When an atom gain or lose an electron it will create ions.In case of resistive material it is also made up of small atoms and there is also presence of ions. When electron passes through any resistive material electron get collide with,atoms,and recombine with ions in the material. The collision of electron and atoms slow down the speed of electron  and due to this it is very difficult for electron to cross this path so this is the cause of resistance in the material. The recombination of electron and ions will release energy in form of heat.

Let us take an example if one person want to pass through the large crowd(ions,atoms) it will be a difficult task and same in there is lower crowd(ions,atoms)  it will be a easy task to pass through the crowd.Please refer below picture for clarification.

Resistance of any material is depends up on below factors

• Length of conductor
• Area of cross section
• Material
Formula for the same is given as below

R=ρ *L/A

Here R is resistance of conductor and ρ is resistivity and L is length of conductor and A is area of conductor.

if length of conductor is increase the resistance is also increased and vice versa.
If area of conductor is increase the resistance is also decreased and vice versa.

so friends we hope you have understand above topic if you have any question please comment below.