Electromagnetic Induction

Question 1

If a wire is moving in a magnetic field and producing and induced current, what must it be doing

Answer 1

Cutting through the magnetic field lines

Question 2

Magnetic Flux

Answer 2

The product of the magnetic flux density when the field is at right angles to the area

Question 3

What is the units of Magnetic Flux

Answer 3

Weber, Wb

Question 4

Flux Density

Answer 4

The measure of the number of lines of magnetic flux per unit cross-sectional area

Question 5

Flux Linkage

Answer 5

The product of the magnetic flux of a coil and the number of turns on the coil

Question 6

What are the three ways to increase the magnetic flux through a coil

Answer 6

1. Increasing the strength of the magnetic field
2. Increasing the area of the coil in the field
3. Moving the coil or the field

Question 7

Faraday’s law

Answer 7

The magnitude of the induced emf is equal to the rate of change of flux linkage

Question 8

Lenz’s law

Answer 8

The direction of any current resulting from an induced emf is such as to oppose the change in flux linkage that is causing the current