Domestic Uses Of Electricity Flashcards
(20 cards)
What is a three-core cable?
A cable that contains three wires, each carrying a different electrical potential.
What is the difference between direct current (d.c.) and alternating current (a.c.)?
D.C. has a constant direction with a potential difference that is always positive or negative
A.C. alternates its potential difference from positive to negative
Why can a live wire be dangerous even when a switch is open?
Touching the live wire can create a large potential difference across the body, resulting in a dangerous current flow
What is the mains electricity voltage in the UK?
230V
What is the frequency of mains electricity in the UK?
50Hz
What are the three wires in a three-core cable and their functions?
Live wire (brown) - carries current to the appliance
Neutral wire (blue) - carries current away from the appliance
Earth wire (green and yellow) - safety wire to prevent appliances from becoming live
What is the role of the earth wire?
The earth wire is a safety wire that stops the exterior of an appliance from becoming live
What happens during the operation of mains electricity?
Current flows through the live and neutral wires
The live wire carries alternating potential
The neutral wire completes the circuit
What is the potential difference of the neutral wire?
0V
A direct current (d.c.) supply is supplied by _______.
cells and batteries
An alternating current (a.c.) supply is used in _______.
mains electricity
What does the casing of a plug do?
It protects the internal components and prevents electric shock
What is the purpose of a fuse in a plug?
To protect the appliance and prevent overheating by breaking the circuit if the current is too high
What does a live wire carry?
Current to the appliance
(The live wire can be dangerous even if a switch in the circuit is open)
What is power in terms of energy transfer?
The rate at which energy is transferred or work is done
An energy transfer of 1J per second is equal to _______.
1W of power
What must be reduced to increase the efficiency of an energy transfer?
The amount of wasted energy
What is the unit of measurement for power?
Watts (W)
What is the unit of measurement for energy transferred?
Joules (J)
What is the unit of measurement for work done?
Joules (J)
