# Preknowledge

 Static electricity

Objectives
 Pupils should be able to:1.define current, emf, pd and resistanc. 2.make calculations involvig current emf, pd and resistance. 3.state Ohm's law.

## INTRODUCTION

Electricity is produced by electrically charged particles which may be any of the following: ions, electrons and protons. When these particles flow or move through a material current electricity is produced.

## ELECTRIC CURRENT

When electric charges flow through a material an electric current is produced. Electric current is defined as the rate of flow of electric charge through acircuit. Electric current=amount of charge/time. I=Q/t where I is current in amperes,A, Q is electric charge in coulombs,C and t is time in seconds,s.