Topic 2.8-2.11 Electricity in the home Flashcards
What is the formula for electrical power
P=IV
power = current x potential difference
When transmitting electricity should the current be high or low and why
low
it generates a lot of wasted heat when high
what do step up transformers do
increase potential difference
decrease current
what do step down transformers do
decrease potential difference
increase current
What is an alternating current
a current that changes direction periodically
What is an direct current
a current that flows around the circuit in the same direction
what is an alternating current caused by
an alternating potential difference
What is direct current supplied by
cells and batteries
what is the standard frequency and voltage of the UK mains supply
230V
50Hz
What is the role of an oscilloscope
display how the voltage changes with time
What colour is the earth wire
green and yellow
what colour is the neutral wire
blue
what colour is the live wire
brown
what colour is the live wire
brown
what are the three wires in a plug
earth
live
neutral
Which wire prevents the electrical casing from becoming live
Earth
Which wire supplies the current to the appliance
live
Which wire completes the circuit, allowing current to flow
neutral
What is the voltage of the neutral wire
0
Explain how fuses work
they are a thin wire that melts if the current is to high
