Permanent And Induced Magnets

Question 1

what are the three main magnetic elements

Answer 1

iron, nickel and cobalt

Question 2

can alloys and compounds be magnetic, and if so why with an example

Answer 2

• compounds and alloys can be magnetic
• if they are made with magnetic elements
• an example is steel, which is an alloy including iron

Question 3

what is the effect of putting a magnetic material near a magnet

Answer 3

the magnetic material is attracted to that object

Question 4

what type of force is created between a magnetic material and a magnet

Answer 4

a magnetic force that is always attractive

Question 5

what do permanent magnets produce all the time

Answer 5

their own magnetic field

Question 6

what is another way of saying something is an induced magnet

Answer 6

it is a temporary magnet

Question 7

when do induced magnets produce a magnetic field

Answer 7

only when they are in another magnetic field

Question 8

what happens to the material when you put any magnetic material into a magnetic field

Answer 8

it becomes an induced magnet

Question 9

what does magnetic induction explain in terms of the attraction an induced magnet feels with a permanent magnet

Answer 9

• it explains why the magnetic force between an induced magnet and a permanent magnet is attractive
• the south pole of the magnet induces a north pole in the material, and vice verse

Question 10

what happens when you take away the magnetic field from an induced magnet

Answer 10

the induced magnet returns to normal and stops producing a magnetic field

Question 11

what determines the rate at which an induced magnet loses its magnetic field and returns to normal

Answer 11

the type of material they are made from

Question 12

what are magnetically soft materials and an example of them

Answer 12

• magnetically soft materials are magnetic materials that lose their magnetism quickly
• examples are pure iron and nickel - iron alloys

Question 13

what are magnetically hard materials and an example of them

Answer 13

• magnetically hard materials are magnetic materials that lose their magnetism more slowly
• an example is steel

Question 14

how are magnetic materials used in fridge doors

Answer 14

there is a permanent magnetic strip in the fridge door to keep it closed

Question 15

how are magnetic materials used in doorbells

Answer 15

they use electromagnets which turn on and off rapidly, to repeatedly attract and release an arm which strikes the metal bell to produce the ringing noise

Question 16

how are magnetic materials used in mri machines

Answer 16

they use magnetic fields to create images of the inside of your body without having to use ionising radiation

Question 17

how are magnetic materials used in cranes

Answer 17

they use induced electromagnets to attract and move magnetic materials