Practise explaining induced voltage, generator action and transformer use with coil diagrams, transmission contexts and voltage-turns calculations.
The diagrams show some equipment that the physicist Ørsted used in an investigation in 1820.
Diagram 1 shows the position of eight compass needles around a wire with no current in the wire.
The compass needles line up with and show the direction of the Earth's magnetic field lines.
Diagram 2 shows the position of the same compass needles when a current is in the wire.
The power supply in diagram 3 is replaced by an ammeter.
When the wire is moved, a current is detected.
Explain which direction the wire is moved in the magnetic field to produce a current in the wire.
Explain why a current is produced in the wire when the wire is moved in the magnetic field.
Diagram 1 shows some of the stages of electricity generation in a nuclear power station.
Diagram 1
High pressure steam transfers energy from the reactor to a turbine.
The turbine spins as the steam passes through it.
Diagram 2 shows a simplified generator connected to the turbine.
Diagram 2
Explain how electricity is generated by the generator.
Transformers are useful in the transmission of electricity.
The diagram shows a step-down transformer.
Give the name of a suitable metal that could be used in the core of the transformer.
State the formula linking input power and output power for a transformer.
The step-down transformer has an input voltage of 275 kV and an output voltage of 230 V.
The transformer has an output current of 95 A.
Calculate the input current to the transformer.
Assume the transformer is 100% efficient.
input current = ............ A
Explain how transformers are useful in the large-scale transmission of electricity.
You may draw a diagram to support your answer.