2a. Magnetism and Induction

Question 1

What directions do magnetic field lines go in?

Answer 1

From North to South

Question 2

What is magnetic field, B measured in?

Answer 2

Tesla (T)

Question 3

What is magnetic flux, Φ?

Answer 3

• The magnetic flux through a coil is the integral of hte normal component of the magnetic field over the area of the coil. Essensially the amount of magnetic field ‘flowing’ through an area.
• Φ = B x A (mag field x area)
• unit: Webers, Wb

Question 4

What is Faraday’s Law?

Answer 4

• V = -N (dφ/dt)
• The emf generated around a coil of a wire is the number of turns (N) times the rate of change of the flux through that coil.
• The minus shows Lenz’s law, showing induced current creates another mag field that acts to resist the movement.