AQA GCSE Electromagnets (Physics)
Electromagnet
An electromagnet is a solenoid with an iron core.
How an electromagnet works.
When the switch is closed a current flows through the coil (solenoid). A magnetic field is created around the solenoid and inside the solenoid, which magnetises the soft iron core to form an electromagnet.
When the switch is opened the current stops flowing through the coil, so the magnetic field is no longer present around solenoid, so the soft iron core demagnetises and an electromagnet is no longer present.
Why is iron used for the core of an electromagnet?
Iron is magnetically soft, this means it is easy to magnetise and demagnetise. It is ideal for use in temporary magnets.
Steel is not suitable for electromagnets because it is magnetically hard, so its harder to magnetise and demagnetise. It is mostly used for permanent magnets.
Making the electromagnet stronger
The strength of the magnetic field of an electromagnet can be increased by:
1. Increasing the current flowing through the coil(solenoid)
2. Increasing the number of turns on the coil(solenoid)
Practice Question
1. State what an electromagnet is
2. Should why it is preferable to use an iron core compared to a steel core in the solenoid
3.Give two ways that strength of the magnetic field of the electromagnet can be increased
Absorption and Emission of EM Radiation
JJ Thomson and Plum pudding model
Ernest Rutherford and the Nuclear Model
Niels Bohr changing the Nuclear Model
Discovering the Proton and Neutron
Measuring radiation from radioactivity
Radiation types and properties
Random nature of radioactive decay
Radioactive contamination or irradiation
Hazards of contamination and irradiation
Studies on the effects of radiation on humans
Different half lives of radioactive isotopes
Nuclear Fission Chain Reaction
Writing nuclear fission equations
Drawing ray diagrams for a concave lens
Drawing Ray Diagram to produce a virtual image for a convex lens
Drawing ray diagram to produce a real image for a convex lens.
Specular and Diffuse Reflection
Seeing Coloured Objects Part 2
Viewing objects through coloured filters
Transparent, Translucent and Opaque
Accordion Content
Accordion Content