Static and current Electiricity Flashcards
Polythene rod
Gains electrons
A Perspex rod
Loses electrons
Earthing
Occurs when a charged object loses its charge to the earth through a conductor
Static electricity
Is a build up of electric charge that can occur on good insulators e.g. Polythene and Perspex rods
Electric current
Is a flow of electric charge (electrons)
Conductors
Are substances which allow electric current to flow through them freely
Insulators
Are substances which do not allow electric current to flow through them
Closed circuit
Is needed for the current to flow, if there is a break in a circuit then the current won’t flow => the electrical energy can’t get through
Energy provided
By a battery or power pack, it is needed to move the current around the circuit
The battery pumps electrons
From its negative end around a circuit
The electrons are attracted
Back to the positive end of the battery
Potential difference
The difference in electrical pressure between the positive and negative ends of a battery/paper pack
Whenever there is a potential difference
Electricity will flow
This potential difference is known as voltage
And is measured in volts
Resistance
Is the opposition to the flow of electrons. The unit is the ohm , and it is measured using an ohmmeter
If a resister
Is placed an electric circuit, it will slow down the flow of electrons
Ohms law
Ohms law states that voltage is directly proportional to current.
DC
Direct current goes in one direction only