Electricity

Question 1

Static Electricity

Answer 1

Static electricity is a build up of electric charge that can occur on good insulators e.g. polythene and perspex rods.

Question 2

Polythene Rod

Answer 2

A polythene rod gains electrons if a woolen cloth is rubbed on it (becomes negatively charged).

Question 3

Perspex Rod

Answer 3

A perspex rod loses electrons if it is rubbed by a woolen cloth (become positively charged).

Question 4

Electric Current

Answer 4

An electric current is caused by the flow of electrons through a good conductor such as metal.

Question 5

Good Insulator

Answer 5

A good insulator does not allow electric current to flow.

Question 6

Closed Circuit

Answer 6

A closed circuit is needed for the current to flow.

If there is a break in a circuit then the current won’t flow and the electrical energy can’t get through.

Question 7

Batteries

Answer 7

Energy provided by a battery or power pack is needed to move the current around the circuit
The battery pumps electrons from its negative end around a circuit. The electrons travel all the way around and are attracted back to the positive end of the battery.

Question 8

Potential Difference

Answer 8

The difference in electrical pressure between the positive and negative ends of a battery/power pack is called the potential difference.
Whenever there is a potential difference electricity will flow.
The potential difference is known as voltage and is measured in volts.

Question 9

Resistance

Answer 9

Resistance is the opposition to the flow of electrons. The unit is the Ohm (Ω), and it’s measured using an ohmmeter.
If a resistor is placed in an electric circuit, it will slow down the flow of electrons.

Question 10

Ohm’s Law

Answer 10

Ohm’s law states that voltage is directly proportional to current.