Summary Physics 1.1, 1.3, 1.4, 3.2, 3.3 & 3.4
1.1 Generating electrical energy
The power station
There are a lot of power stations in the Netherlands which create energy. This is how they work:
o Large burners burn natural gas, coal or another fuel. The heat heats water in a boiler,
which creates water vapor
o The steam passes the blades of a turbine, and make the rotors spin.
o A generator turns this spinning motion into electricity.
o The waste steam is passed through a condenser and turns back into liquid water again.
Generating an induced voltage
A generator uses motion to create energy, a magnet moves through a coil, in
and out. This motion creates an alternating voltage. This effect is also known
as induction. The alternating voltage is also known as induced voltage.
In real life, a spinning motion is used. Where a magnet is spinning inside a
tube of soft iron, which is iron which can magnetize and demagnetize very
quickly.
If the magnet is rotating, the soft iron will keep being magnetized differently. In the
picture you can see that from the field lines. Which show the direction of the
magnetic field
Electric power
Some power stations can supply more electrical energy
o If you want to compare them you have too look at their capacity, their
electrical power. The electrical power is the maximum amount of energy a
station can supply per second. A power station in Rdam can supply 870
MW.
Electrical devices like led lamps consume electrical energy, the energy doesn’t go
away but is in a different form, in this case light and heat.
o Every electrical device has their own power rating; the energy it uses per s.
Calculating the energy consumption
E=Pxt
o E = is the energy in joules (j)
o P is the power in watts (W)
o t is the time in seconds (s)
P = E/t
, o 1 watt is the same as 1 joule per second
In the test, write large numbers in scientific notation!
1.1.1 You can describe the component parts of a power station and say what they do.
1.1.2 You can explain how an induction voltage is generated in an alternator (dynamo).
1.1.3 You can explain what is meant by the electrical power (supplied or consumed).
1.1.4 You can calculate the energy consumption of an electrical device in units of joules.
1.1.5 You can use prefixes or powers of ten to express small, every day and very large amounts
of energy in joules.
1.3 Electricity in the home
A domestic electrical system
A network of electrical wiring that runs through a home: the
domestic system
The branches are in parallel, so the voltage is the same
everywhere.
U = U1 = U2 = U3 = … = 230V
U is the voltage across the entire domestic system
U1, U2, etc. are the voltages across the first, second, etc. branches
Each group has his own group switch
It is parallel, so the current (I) is divided
Itot = I1 + I2 + I3 + …
Itot is the total current of all the groups
I1, I2, I3 are the currents through the first, second and third branches.
Connecting a device
A main socket has a soldi copper core and PVC insulation layer around them. The brown wire is
the live wire and the blue one is the neutral wire.
The live wire has an alternating voltage of 230 V
The neutral wire has no voltage, and is only there to complete the circuit.
A switch wire is only live when the switch is ‘on’.
1.1 Generating electrical energy
The power station
There are a lot of power stations in the Netherlands which create energy. This is how they work:
o Large burners burn natural gas, coal or another fuel. The heat heats water in a boiler,
which creates water vapor
o The steam passes the blades of a turbine, and make the rotors spin.
o A generator turns this spinning motion into electricity.
o The waste steam is passed through a condenser and turns back into liquid water again.
Generating an induced voltage
A generator uses motion to create energy, a magnet moves through a coil, in
and out. This motion creates an alternating voltage. This effect is also known
as induction. The alternating voltage is also known as induced voltage.
In real life, a spinning motion is used. Where a magnet is spinning inside a
tube of soft iron, which is iron which can magnetize and demagnetize very
quickly.
If the magnet is rotating, the soft iron will keep being magnetized differently. In the
picture you can see that from the field lines. Which show the direction of the
magnetic field
Electric power
Some power stations can supply more electrical energy
o If you want to compare them you have too look at their capacity, their
electrical power. The electrical power is the maximum amount of energy a
station can supply per second. A power station in Rdam can supply 870
MW.
Electrical devices like led lamps consume electrical energy, the energy doesn’t go
away but is in a different form, in this case light and heat.
o Every electrical device has their own power rating; the energy it uses per s.
Calculating the energy consumption
E=Pxt
o E = is the energy in joules (j)
o P is the power in watts (W)
o t is the time in seconds (s)
P = E/t
, o 1 watt is the same as 1 joule per second
In the test, write large numbers in scientific notation!
1.1.1 You can describe the component parts of a power station and say what they do.
1.1.2 You can explain how an induction voltage is generated in an alternator (dynamo).
1.1.3 You can explain what is meant by the electrical power (supplied or consumed).
1.1.4 You can calculate the energy consumption of an electrical device in units of joules.
1.1.5 You can use prefixes or powers of ten to express small, every day and very large amounts
of energy in joules.
1.3 Electricity in the home
A domestic electrical system
A network of electrical wiring that runs through a home: the
domestic system
The branches are in parallel, so the voltage is the same
everywhere.
U = U1 = U2 = U3 = … = 230V
U is the voltage across the entire domestic system
U1, U2, etc. are the voltages across the first, second, etc. branches
Each group has his own group switch
It is parallel, so the current (I) is divided
Itot = I1 + I2 + I3 + …
Itot is the total current of all the groups
I1, I2, I3 are the currents through the first, second and third branches.
Connecting a device
A main socket has a soldi copper core and PVC insulation layer around them. The brown wire is
the live wire and the blue one is the neutral wire.
The live wire has an alternating voltage of 230 V
The neutral wire has no voltage, and is only there to complete the circuit.
A switch wire is only live when the switch is ‘on’.
