## 2008-10-09

### Electric current as the rate of charge flow

Electric current as the rate of charge flow

During the thunderstorm, large electric fields are built up in the region between clouds and the earth, as well as in the region between the clouds themselves. This electric field is produced by friction between the water molecules in the clouds and the air molecules causing charges to build up in the clouds.

When the electric field between the clouds and the earth sufficiently large it can ionize the air molecules producing a pathway for the huge quantity of charge on the clouds to be discharged as lightning. We can generate this type of charges using the Van de Graff generator.

The most common electric current is produced by the power station and distributed to our houses. Electric current can also be produced by batteries which are used in many devices. It is very important to have a way to measure and quantify electric current.

The magnitude of an electric current is the rate of flow of electrical charges that pass a given point in an electric circuit. Current is measured in coulombs per second or ampere, A.

Total charge = current x time taken

Current = Total charge flowing through a point / time taken.

Q = It

where

I = Current
t = Time

#### 1 comment:

Anonymous said...

how do we solve it?