P7 Magnetism and Electromagnetism

Question 1

what is the motor effect

Answer 1

when a current carrying wire is put between magnetic poles and the magnetic field around the wire interacts with the magnetic field it has been placed in. causing the magnet and the conductor to exert a force on one another causing the wire to move

Question 2

How to induce the motor effect

Answer 2

to experience the full force the wire has to be at 90 degrees to the magnetic field. if the wire runs parallel to the magnetic field it won’t experience any force at all. at angles in between it’ll feel some force

Question 3

Which direction does the force act during the motor effect and how should you show the direction of the force

Answer 3

the force always acts at right angles to the magnetic field of the magnets and to the direction of the current in the wire. the best way of showing the direction of the force is to apply a current to a set of rails inside a horseshoe magnet.

Question 4

how to find the size of the force in the motor effect

Answer 4

the force acting on a conductor in a magnetic field depends on three things:
1) the magnetic flux density - how many field lines there are in a region. this shows the strength of the magnetic field
2) the size of the current through the conductor
3) the length of the conductor that’s in the magnetic field
when the current is at 90 degrees to the magnetic field it is in the force acting on it can be found using an equation - force = magnetic flux density x current x length