Figure 9. Generation of An EMF In An Electrical Conductor

Electronic Principles
Page Navigation
17

the emf is developed by the action between the magnetic field

and the electrons in a conductor (shown in figure 9).

FIGURE 9. GENERATION OF AN EMF IN AN ELECTRICAL CONDUCTOR.

When a magnetic field moves through a stationary metallic

conductor, electrons are dislodged from their orbits. The

electrons move in a direction determined by the movement of the

magnetic lines of flux. This is shown in figure 10 on the

following page.

The electrons move from one area of the conductor into another

area. The area that the electrons moved from has fewer negative

charges (electrons) and becomes positively charged. The area

the electrons move into becomes negatively charged. This is

also shown in figure 10.

The difference between the charges in the conductor is equal to

a difference of potential (or voltage). This voltage caused by

the moving magnetic field is called the electromotive force

(emf).

In simple terms, the action of a moving magnetic field on a

conductor can be compared to the action of a broom. Consider

the moving magnetic field to be a moving broom. As the magnetic

broom moves