How deeply should students be able to explain the production of electromagnetic radiation?
From the study of Unit 4 Electric power, students should be aware of Faraday’s law of magnetic induction that a changing magnetic field induces an emf, also described as a voltage drop or a potential difference. They will understand that a potential difference causes charge to move. They will now need to appreciate that this causing of the movement of charge can also be explained by the concept of an electric field, and that an electric field is a property of space, in the same way as a magnetic field. Students should understand that an electron has an electric field in the space around it such that if another charge is placed in that field, it will experience a force, and when an electron is accelerated, its electric field is affected. As a consequence of Maxwell’s equations, a changing electric field produces a changing magnetic field, and from Faraday’s law, this changing magnetic field induces a repeatedly changing electric field, and so producing electromagnetic radiation.
