Experiment to demonstrate the forces between currents and the definition of the ampere

Draw a diagram of this experiment

Method

Set up apparatus as shown and turn on power

Result (A)

Aluminium strips in A repel each other

Result (B)

Aluminium strips in B are attracted to each other

What is the principle behind this experiment

If a charged particle moving at a constant speed enters a uniform magnetic field and moves at right angles to the field it will move in a circular path

Draw a charged particle moving in a uniform magnetic field

Current moves in the …… to electrons

Opposite direction

Explain what happens when an electron enters a magnetic field

Experiences a force perpendicular to the magnetic field and the direction of travel of electrons. This happens continuously and constitutes a centripetal force which causes the electrons to move in a circular path.

Symbol for arrow going into page

Symbol for arrow going out of page

Symbol for arrow for direction of a magnetic field