1. What we will do today State what is meant by electric current. State the difference between conductors and insulators. State how we measure electric current. State how we can measure electric charge.

2. What is Electric Current? In a conductor, electrons are allowed to move freely. An electric current is a flow of electric charges, usually electrons. Electrons are very small negatively charged particles. In a closed circuit electric current moves from the negative terminal to the positive terminal of a battery or power source.

3. Conductors and Insulators Conductors – allow electric current to flow through. E.g metals and carbon Insulators – do not allow electric current to flow through. E.g. non-metals like air, plastic & wood Super Electric Human (India) Who can Conduct High Voltage Electricity Through his Body.FLV - YouTubeSuper Electric Human (India) Who can Conduct High Voltage Electricity Through his Body.FLV - YouTube

4. Measuring Electric Current An ammeter is an instrument that measures electric current. Electric current has the unit amperes (A).

5. Measuring Electric Charge Electric ‘current’ is a flow of electric ‘charge’ around a circuit. We find that the relationship between the two is given as: Charge = Current x time Q = I t Charge is measured in Coulombs (C).

6. Example 1 I = 5 A t = 30 s Q = ?

7. Example 2 I = ? t = 5 mins Q = 150 C

8. Example 3 I = 100 mA t = ? Q = 5 C

9. 2005, Qu: 9