P4 - Safe Electricals

?
What is the name of a device that changes resistance?
Rheostat or variable resistor
1 of 15
How can you make the wire have more resistance?
By making it a longer length or thinner
2 of 15
What is voltage measured in?
Volts (V)
3 of 15
How is voltage measured?
Using a voltmeter connected in parallel
4 of 15
For a fixed resistor, as the voltage across it increases...
the current increases
5 of 15
For a fixed power supply, as the resistance increases...
the current decreases
6 of 15
What is the formula for resistance?
resistance = voltage / current
7 of 15
What is resistance measured in?
Ohms
8 of 15
What does the live wire do?
Carries a high voltage around the house
9 of 15
What does the neutral wire do?
Completes the circuit, providing a return path for the current
10 of 15
What is the main purpose of fuses and earth wires?
Stop a person receiving an electric shock if they touch a faulty appliance. As soon asthe case becomes 'live', a large current flows in the earth and live wires and fuse 'blows'
11 of 15
What does the earth wire do?
Is connected to the case of an appliance to prevent it becoming live
12 of 15
What does the fuse do?
Contains wire which melts, breaking the circuit, if the current becomes too large
13 of 15
What happens if the fuse melts the wire? How is restored?
Doesn't need to be replaced to restore power, it can be re-set
14 of 15
What is power?
The rate at which an appliance transfers energy
15 of 15

Other cards in this set

Card 2

Front

How can you make the wire have more resistance?

Back

By making it a longer length or thinner

Card 3

Front

What is voltage measured in?

Back

Preview of the front of card 3

Card 4

Front

How is voltage measured?

Back

Preview of the front of card 4

Card 5

Front

For a fixed resistor, as the voltage across it increases...

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Science resources:

See all Science resources »See all Safe Electricals resources »