Electric charges and fields 02

 

Hey friends, In this blog you will understand what are conductors and insulators, what is earthing or grounding, what is electrostatic induction and how we can charge a sphere by induction process. 

Conductors and insulators

Conductors -  The substances through which electric charges can flow easily are called conductors. 

The conductors contain a large no. Of free electrons which make then good conductor of electricity. 

For ex - silver, copper, aluminum, human, animal bodies, acids, graphite etc. 

Insulators - The substances through which electric charges can not flow easily are called insulators. 

Free electron is tightly bond with the nucleus in it so there is an absence of free electrons the insulators can not conduct electric charges. 

                                Note

A metal rod held in hand and rubbed with wool not developed any charge ( the charge developed on the metal rod is transferred to the earth through the human body) , we can electrify the rod by providing it a plastic or a rubber handle. 

       Earthing or Grounding

When a charged body is brought to contact with earth it's entire charge possess to the ground in the form of a momentary current. 

This process in which a body shares its charges with the earth is called grounding. 

When a negative plate connected with earth then, the electrons start to flow from high charge density plate to low charge density (earth) and plate becomes neutralise after some time. 

      Electrostatic induction

When we bring a positively charged glass rod near the conducting rod the electrons of the conducting rod gets attracted towards it's closer end while it's further end becomes electron deficient. 

Thus, the closer end acquires negative charge while the further end acquires equal positive charge. 

As soon as glass rod is taken away the charges at its both ends disappear. 

All this phenomena is known as Electrostatic induction. 

Charging of a sphere by induction