Magnetism Flashcards
Magnetic field
A region where a magnet or ferromagnetic material experiences a magnetic force. The magnetic field presence is detected when another magnet is brought into the region. It experiences a non contact force of repulsion and attraction when it enters a magnetic field
What is a ferromagnetic material
Materials that are attracted to a magnet when they are placed in its magnetic field.
Examples of ferromagnetic material
Iron, nickel, cobalt and alloys
How does iron display its ferromagnetic characteristic
Iron fillings align themselves with the field lines in a magnetic field
The poles of the magnet
Ends of a magnet with high concentration of magnetic field lines.
The north and south pole
Point towards the earth’s magnetic north and magnetic south
A denser concncetration of field lines show
A greater magnetic field strength in that region
Magnetic fields lines are
Continuous and never cross each other
The magnetic north pole is actually a south pole because
The north pole is attracted to the magnetic north and since like poles repel it must mean that the magnetic north is actually a south pole.
Magnetic field lines face inward at the magnetic north point which should only occur for the south pole therefore it is a South pole.
Effects of Changes in distance and orientation of the magnetic field strength
Decrease in magnetic field strength as distance increases and decreases the concentration of magnetic field lines near the magnet.
Nearer to the magnet, the rate of change in magnetic field strength is greater
The magnetic field strength decreases with increasing distance (following the inverse square law) and varies with orientation, with maximum strength occurring when perpendicular to magnetic field lines and minimum strength when parallel.
Induced
Non magnetic materials
If you place an iron paper clip to a permanent magnet without touching
The paperclip will become an induced magnet with the end nearest to the magnet having an opposite polarity of that of the magnet
