ELECTRICITY

Question 1

STATIC ELECTRICITY

Answer 1

a build up of electric charge

Question 2

POLYTHENE ROD

Answer 2

gains electrons if a woollen cloth is rubbed on it
(becomes negatively charged)

Question 3

PERSPEX ROD

Answer 3

loses electrons if it is rubbed by a woollen cloth
(becomes positively charged)

Question 4

what is an electric current?

Answer 4

An electric current is caused by the flow of
electrons through a good conductor such
as a metal
• A good insulator does not allow electric
current to flow

Question 5

what can electrical energy be converted into

Answer 5

light
heat
kinetic
sound

Question 6

what is potential difference

Answer 6

The difference in electrical pressure
between the positive and negative ends is
called the Potential Difference
• Whenever there is a potential difference
electricity will flow
• This potential difference is known as
Voltage and is measured in volts

Question 7

resistance

Answer 7

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

Question 8

what do we need resistors for

Answer 8

• As the electrons push to get through the
resistor the electrical energy is changed to
heat energy
• When Resistors such as a light bulb
filament or the heating coil of a kettle is
placed in a circuit they resist the current
and thus get hot

Question 9

Alternating Current

Answer 9

• Alternating current changes very quickly,
many times a second
• This is how the current is supplied by the
ESB
• AC can be converted to DC using a
rectifier, smoothed using a capacitor