Electricity In The Home Flashcards
what are the two types of electricity supplies
alternating and direct currents
what does ac and dc stand for
alternating current and direct current
what the current in ac supplies doing
constantly changing direction
what are alternating currents produced by
alternating voltages in which the positive and negative ends keep alternating
what is the uk mains supply
an ac supply at around 230V
what is the frequency of the ac mains supply
50 cycles per second or 50Hz
what do cells and batteries supply (in contrast)
direct current (dc)
what is direct current
current that is always flowing in the same direction and is created by direct voltage
what are most electrical appliances connected to the mains supply by
three-core cables
what does the term three-core cables mean
they have three wires inside them, each with a core of copper and a coloured plastic coating
what does the colouring of the insulation on each cable show
its purpose
why are the colours of the cables always the same on every appliance
so that its easy to tell the different wires apart
what is the colour of the neutral wire and what does it do
- blue
- completes the circuit and carries away current
- electricity flows in through live wire and out through neutral
- its around 0V
what is the colour of the live wire and what does it do
- brown
- provides the alternating potential difference from the mains supply
- potential difference is about 230V
what is the colour of the earth wire and what does it do
- green and yellow
- protecting the wiring and for safety
- stops appliance casing from becoming live
- doesnt usually carry a current, only when there is a fault
- its 0V
