Write a short note on direct current (DC).

Explanation

DC : This current flows only in one direction. If the voltage does not change with time , the current remains constant.
This is shown in figure 13.32.

When a cell or battery is used to obtain DC, the voltage goes on decreasing also decreases with time .
In a circuit , the electric current flows the positive terminal of the cell or battery to the negative terminal in the external circuit, that means it flows only in one direction.
Thus , the current obtained due to cell or battery is unidirection . It is called direction current (DC).
A generator that produces direction current is called a DC generator which is also called a dynamo.
DC is used in radio, cell phone , watch, laptop etc.