[7] Magnetism

what are 3 magnetic materials

nickel, cobalt and iron

what are the properties of soft magnetic materials

they are easy to magnetize and demagnetize. These materials are used for making temporary magnets.​

what are the properties of hard magnetic materials

they are those which retain their magnetism even after the removal of the applied magnetic field. They are difficult to demagnetise and are used to make permanent magnets

 

how can magnetism be induced in magnetic materials

by placing them into a magnetic field

what is the definition of a magnetic field?

the region around a magnet where a magnetic force can be detected

what is the definition of magnetic field lines

a visual tool used to show the direction shape and strength of a magnetic field

direction of magnetic field lines

north to south poles

how do i know the strength of magnetic field lines

density of lines (how close they are)

what can magnetic field lines NEVER do

cross eachother

how do i detect the shape of a magnetic field only? [3]

• place a bar magnet beneath a sheet of paper

• sprinkle iron fillings on top of the paper

• tap paper gently and the field will become visible

how do detect the shape and direction of a magnetic field [3]

• select a starting point next to a pole

• mark the position of the compass needle

• move the compass so that the back of the needle is touching the dot

• repeat

• eventually a line can be made by joining the dots

how can you make a material loose its magnetic field and why does this work?

by bashing it with a hammer, or heating it up this removes its magnetic field because the internal alignment of its magnetic domains gets disturbed