P7 Flashcards
What are the poles of a magnet?
Places where the magnetic forces are strongest. When two magnets are brought close together they exert a force on each other. Two poles repel each other . Two unlike poles attract each other. Attraction and repulsion between two magnetic poles are examples of non contact forces.
What do compasses show?
Compass points to the direction that the magnetic field is in
What is a permanent magnet?
Produces its own magnetic field
What is an induced magnet?
Material that becomes a magnet when it is palced in a magnetic field. Induced magnets always cause a force of attraction. When removed from a magnetic field an induced magnet loses all of its magnetism quickly
What is a magnetic field ?
A region around a magnet where a force acts on another magnet or on a magnetic material (iron,steel,cobalt and nickel) is called the magnetic field.
What is always the force between a magnet and a magnetic material?
A force of attraction
What does the strength of the magnetic field depend on?
Distance from the magnet. The field is strongest at the poles of the magnet
What effects the direction of a magnetic field?
Given by ghe direction of the force that would act on another north pole placed at the point. The direction of a magnetic field line is from the north pole of a magnet to the south pole of a magnet
How do compasses show the earths magnetic fields?
Contain a small bar magnet. The earth has a magnetic field. The compass needle points in the direction of the earths magnetic field
What is createdwhen a current flows through a conducting wire ?
A magnetic field is produced around the wire. The strength of the magnetic field depends on the current through the wire and the distance around the wire.
What is a solenoid?
A coil of a wire. It increases the strength of the magnetic field created by a current through a wire. The magnetic field inside the solenoid is strong and uniform
What is the shape of the magnetic field around a solenoid?
Similar to the magnetic field around a bar magnet
How to increase strength of magnetic field of a solenoid?
Add an iron core .
What is an electromagnet?
A solenoid with an iron core
What is the motor effect?
When a current carrying wire is put between magnetic poles , the magnetic field around the wire interacts with the magnetic field it has been placed in . This causes the magnet and the conductor to exert a force on each other. This is called the motor effect and can cause the wire to move.
