3.14 Motor Effect

Question 1

What is the motor effect?

Answer 1

When a current-carrying conductor (e.g. a wire) is put near a permanent magnet (or in an external magnetic field) , the two magnetic fields interact with each other. This causes a form to be exerted on both the wire and the magnet. This is called the motor effect - this usually causes the wire to move

Question 2

What position does the current-carrying wire have to be to have the maximum motor effect?

Answer 2

At 90 degrees to the magnets

Question 3

How can you calculate the force acting on a current-carrying conductor?

Answer 3

Force (N) = magnetic flux density (T) x current (A) x length of conductor (m)

Question 4

Using flemings left-hand rule, what does each finger represent?

Answer 4

• The thumb represents Force
• The first finger represents the direction of the magnetic Field
• The second finger represents the direction of the current

Question 5

What is magnetic field strength (also known as magnetic flux density) is measured in:

Answer 5

Teslas (T)