Faraday's law of induction states that the induced electromotive force (emf) in any closed circuit is equal to the time rate of change of the magnetic flux through the circuit. It explains how transformers, inductors, motors and generators work by relating the induced emf to the changing magnetic flux. The law combines with Lenz's law, which describes the direction of induced current. Specifically, the induced emf is equal to the product of the magnetic field strength, length of the coil, and its velocity of removal from the field.

1. Faraday’s Law
By BT and TP

2. What is Faradays law
• Faraday's law of induction is a basic law of
electromagnetism relating to the operating
principles of transformers, inductors, and
many types of electrical motors and
generators.

3. EMF
• The induced electromotive force (emf) in
any closed circuit is equal to the time rate
of change of the magnetic flux through the
circuit.

4. How Faraday’s Law Combines With
Lenz’s Law
If Faraday’s Law shows how to calculate
the induced emf and Lenz’s Law shows
the direction of the induced current you
can combine the two equations to get.ε
ε = Blv

5. The law..
• Faraday’s law of electromagnetic induction
states that the induced emf in a circuit is
equal to the rate of change of flux linkage
throughout the circuit.
ε = Bl/Δt = Blv

6. Test
• A rectangular coil of length 40mm and width 25mm has
20 turns. The coil is in a uniform magnetic field of 68mT.
What is the flux linkage when coil is perpendicular to field
lines?
• 1.4 mWb
• The coil is removed in 60ms. Calculate the mean
reduced emf?
• 23mW
Click for answers

7. Test
• A rectangular coil of length 40mm and width 25mm has
20 turns. The coil is in a uniform magnetic field of 68mT.
What is the flux linkage when coil is perpendicular to field
lines?
• 1.4 mWb
• The coil is removed in 60ms. Calculate the mean
reduced emf?
• 23mW
Click for answers