 # ELECTRIC CURRENT – Introduction and Quiz

We use the electric appliances like TV, refrigerator, electric motor, electric torch etc. Electricity is now an essential item in our life and we cannot imagine life without it.  Every month we pay for electricity by paying electricity bill. We use many terms for electricity like voltage, current, short circuit , resistance etc. We will look into these terms and concepts in this chapter.

ELECTRIC CURRENT

When we switch on an electric torch, the current flows and electric bulb lights dark room. When battery is connected to the circuit, current flows in the circuit due to movement of   electrons.

Electric current is a flow of electrons in a conductor which can be measured by amount of charge flowing through a particular cross section area in unit time.

Current I = Q / t

SI unit of electric charge ‘Q’ is Coulombs and ‘t’ is in seconds in SI units. SI Unit for Current ‘I’ is Ampere.

Those substances through which electric charge can flow are called conductors. Those substances through which electricity cannot flow are called insulators. All the conductors have some electrons which are loosely held by their atoms. These electrons are called free electrons. The direction of electric current is from positive terminal to negative terminal through the circuit but direction of flow of electrons is opposite to direction of flow of current.

Charge of one electron is 1.6 x 10-19 Coulomb.

On the basis of your understanding of the above topic, answer the following questions–