## Wednesday, March 16, 2011

### Physics Form 5: Chapter 2 - Current and Potential Difference

• Current is the rate of flow of charge.
• The flow of current is due to the flow of electrons in conductor.
• Direction of current flow is opposite to the direction of electron flow.

•  Potential difference is the work done to flow one unit of charge from one point to another point.
• Unit of potential difference is volt.

Consider the task of moving a charge within a uniform electric field from location A to location B. In moving the charge against the electric field from location A to location B, work will have to be done on the charge by an external force. The work done on the charge changes its potential energy to a higher value; and the amount of work that is done is equal to the change in the potential energy. As a result of this change in potential energy, there is also a difference in electric potential between locations A and B. This difference in electric potential is  formally referred to as the electric potential difference

Click on the diagram below to play!