Domestic uses of electrecity P5 Flashcards
d.c.
current flows in one direction so the graph of p.d over time has to always be positive or negative
Full form of d.c
direct current
Full form of a.c
Alternating current
What is a source of a d.c?
Batter, cell
a.c
when current continuously changes direction
a.c. current goes to ….
positive and negative terminal at a very rapid rate
How much voltage does the main’s power have
230 V
What does hertz mean
How many times it has changed direction in a second
How many hertz does main’s power have
50
Where does mains electrecity come
Come from power station
National grid
System that transports electrecity
Step up transformer… p.d
increases
Increase p.d means
reduced energy loss
Why decrease p.d
so electricity can get to our houses safely
Frequency=
1/period
Live wire
This carries the current to the appliance. Touching this can be deadly
Neutral wire
This completes the circuit and it is usually at 0V
Earthwire
This’earths’ the appliance in case one of the wires touches the casing. Also prevents the blue and brow wires touching
Fuse
This stops the flow of current from getting high
What colour is the Live wire
brown
What colour is the Earth wire
Yellow/ green
What colour is the neutral wire
Blue
Why is plastic used on cables
Even if the live wire touches it won’t do anything because insulator
Power
Measure of the energy transferred electrically each second
