Physics current electricity
Ways to protect the user/appliance in a domestic setting- ✅Insulation
Double insulation
EARTHING
Fuses
Circuit breakers
✅
How insulation protects the user/appliance- Wires are insulated with
plastic, to prevent an electric shock occurring when the user touches it
✅
How DOUBLE insulation works- The appliance is completely covered in a
layer of an insulating material, e.g. plastic, which means that there is no
possibility of a current passing through to the user. This is usually used
instead of an earth wire.
✅
How earthing works- In addition to the (brown) live wire (that carries the
current into the appliance), and the (blue) neutral wire (that carries the
current out of the appliance) the (green and yellow) earth wire provides a
path of very low resistance to the ground, so electrical energy flows through
it rather than through the user.
✅
How fuses work- The fuse is connected to the live wire. The value of the
fuse must be slightly higher that what the appliance needs to function.
When the current is too high, the fuse melts, breaking the circuit and
protecting the appliance and user.
✅
How circuit breakers work- Circuit breakers are resettable fuses. If the
current exceeds a certain value, an electromagnet will separate a pair of
contacts, breaking the circuit. They are more practical than fuses.
✅
What happens when current flows through a resistor- The temperature
increases, as a result of the electrons (that are flowing through the
conductor as current) colliding with ions in the lattice and transferring some
Ways to protect the user/appliance in a domestic setting- ✅Insulation
Double insulation
EARTHING
Fuses
Circuit breakers
✅
How insulation protects the user/appliance- Wires are insulated with
plastic, to prevent an electric shock occurring when the user touches it
✅
How DOUBLE insulation works- The appliance is completely covered in a
layer of an insulating material, e.g. plastic, which means that there is no
possibility of a current passing through to the user. This is usually used
instead of an earth wire.
✅
How earthing works- In addition to the (brown) live wire (that carries the
current into the appliance), and the (blue) neutral wire (that carries the
current out of the appliance) the (green and yellow) earth wire provides a
path of very low resistance to the ground, so electrical energy flows through
it rather than through the user.
✅
How fuses work- The fuse is connected to the live wire. The value of the
fuse must be slightly higher that what the appliance needs to function.
When the current is too high, the fuse melts, breaking the circuit and
protecting the appliance and user.
✅
How circuit breakers work- Circuit breakers are resettable fuses. If the
current exceeds a certain value, an electromagnet will separate a pair of
contacts, breaking the circuit. They are more practical than fuses.
✅
What happens when current flows through a resistor- The temperature
increases, as a result of the electrons (that are flowing through the
conductor as current) colliding with ions in the lattice and transferring some
