Current mains and electricity Flashcards
What are hazards with electricity state why.
Long cables- larger resistance (resistance is proportional to length of wire) This means the wire may heat up causing a fire
Damaged plugs - plastic insulation is missing or plastic cover is broken then live wires are exposed and there will be a risk of an electric shock
Frayed cable - The plastic insulation is no longer covering live wire (increasing risk of shock)
Water around socket- water can get into electrical equipment and allows for electricity to conduct to the outside and cause an electrical shock
Pushing metal into sockets- metal is a very good conductor (it has free electrons) so there is a risk of an electrical shock
what is the importance of the plastic plug
Plastic is an insulator
current can no pass through the insulator
Prevents the risk of electric shock
What is the importance of wire covering
plastic is soft
plastic is an insulator, current can not pass through it reducing the risk of electric shock
wires will not short circuit when encased in the same cable
what is the importance of prongs in the plug
Prongs are made out of brass
brass is a metal which a good conductor (has free electrons) Allows current to pass through easily. Brass is not malleable (hard) so prongs will not bend
what is the importance of the copper wires in plugs
Copper is a metal which is a good conductor and is relatively cheap.
copper is also ductile which means it can be drawn into wires.
what colour is the live wire
brown
what colour is the Neutral wire
Blue
what colour is the Earth wire
stripy
green and yellow stripes
which wire is connected to the fuse
the live wire
what is the earth wire connected to and what is it there for
Earth wire is there for safety
connected to the metal casing of the plug
earth wire takes any excess charge and dissipates it to the ground
How does the earth wire work to prevent the risk of an electric shock
Erath wire is connected to metal casing
earth wire acts as the neutral wire.
A big current flows through the live wire into earth wire
fuse wire overheats –causing it to melt
circuit surges causing it to break
stopping/disallowing anymore current from passing through
what is the function of the fuse wire
If the current in a fuse is too high, (the temperature is higher than the wire in the fuse can take)
This causes the fuse wire to overheat
the fuse wire melts
breaking the circuit stopping any current from passing through
What causes the fuse wire to heat up
Current contains electrons
As current flows through fuse the electrons collide with its ionic lattice
They transfer energy as heat which dissipates into the surroundings
What causes the Resistor wire to heat up
Current contains electrons
As current flows through wire the electrons collide with metal ions
Producing energy
What causes the Metal wire to heat up
Current contains electrons
As the electrons flow through the wire they collide with the metal ions
They transfer energy as heat which dissipates to it’s surroundings
