Electromagnetism Faraday & Maxwell
Maxwell James Clerk Faraday ( ) was an Scottish scientist. He was a gifted mathematician and one of the first scientists to take seriously Faraday’s notion of electric and magnetic fields permeating the universe.
Maxwell’s Equations: 1 Gauss’s Law: Electric field lines begin on positive charges and end on negative charges. The electric flux (field lines leaving an enclosed surface) is proportional to the charge density in a particular volume.
Maxwell’s Equations: 2 There is no such thing as a magnetic monopole.
Maxwell’s Equations: 3 Faraday’s Law: The voltage accumulated around a closed circuit is proportional to the rate of change in magnetic flux.
Maxwell’s Equations: 4 Ampere’s Law: A magnetic field is produced by a changing electric current and by a changing electric field.
Implications A moving charge creates a changing electric field. A changing magnetic field leads to a changing electric field. The electric field is at right angles to the magnetic field. A changing electric field creates a changing magnetic field. The magnetic field is at right angles to the electric field.
Electromagnetic waves Oscillating charges set up transverse waves in the electric and magnetic fields. Waves carry energy in a direction perpendicular to both E and B. Matter is made of oscillating charges.
Calculate Calculate the speed of an electromagnetic wave. Recall values for permittivity 0 = 4 x T m / A and permeability 0 = 8.85 x C 2 / Nm 2
Light is an electromagnetic wave!
Science & Religion God said… and there was light.