Carbon a Nonmetal ! But why it is used in Dc motor brushes ?

           One reason is the high melting temperature of carbon. The inductances of the energized windings, and the mechanics of a brush type motor or generator make arcing and sparking an unavoidable characteristic  of the machine...

Why 50 hertz frequency in India ?

IT STARTS FROM THE BEGINNING OF ELECTRICITY- Early in the history or electricity, Thomas Edison's General Electric  company was distributing DC electricity at 110 volts in the United States.  Then Nikola Tesla devised a system of three-phase AC electricity at ...

Effects of electric shock on human body...

Two main types of effects of Electric shock : Stimulation of muscles and nerves We've all felt that buzzing or tingling sensation without experiencing injury. A current as low as 0.25 milliamperes (mA) can cause this feeling. Starting at 10 mA, most people cannot...

What is the diffrence between an insulator and dielectric ???

What is the difference between an insulator and a dielectric? This is a question that can be confusing to many engineers. This is because the terms "insulators" and "di-electrics" are often used interchangeably. Insulators are substances which permit very less current...