Question

What are Dielectrics? 

Explain polar and non polar dielectric

Answer 1

It is an insulating material (non-conducting) which has no free electrons. But a microscopic displacement of charges is observed in the presence of an electric field. It is found that the capacitance increases as the space between the conducting plates are filled with dielectrics.   

Polar and Non-polar Dielectrics: 

Each atom is made of a positively charged nucleus surrounded by electrons. If the centre of the negatively charged electrons does not coincide with the centre of the nucleus, then a permanent dipole (separation of charges over a distance) moment is formed. Such molecules are called polar molecules. If a polar dielectric is placed in an electric field, the individual dipoles experience a torque and try to align along the field  ..

In non-polar molecules, the centres of the positive and negative charge distributions coincide. There is no permanent dipole moment created. But in the presence of an electric field, the centres are slightly displaced. This is called induced dipole moments.  

  

 

It is an insulating material (non-conducting) which has no free electrons. But a microscopic displacement of charges is observed in the presence of an electric field.