Magnetism

Question 1

all magnets have a … and a …

Answer 1

all magnets have a north pole and a south pole

Question 2

the magnetic field flows from … to …

Answer 2

the magnetic field flows from the North pole (N) to the South pole (S)

Question 3

what are ferromagnetic materials?

Answer 3

materials that can be magnetised, which are also the ones that are strongly attracted to a magnet

Question 4

what are three examples of ferromagnetic materials?

Answer 4

iron, nickel, and cobalt

Question 5

what are permanent magnets?

Answer 5

objects made from magnetised material and produce continual magnetic fields

Question 6

what are three examples non-magnetic materials?

Answer 6

rubber

copper

wood

Question 7

are all substances magnetic?

Answer 7

no

Question 8

what test can you perform to discover whether a substance is magnetic?

Answer 8

get a sample of the substance and hold it against a magnet

if it attracts then it is magnetic

if if does not then it is non-magnetic

Question 9

what do magnets do to other magnets?

Answer 9

repel and attract

Question 10

what do magnets do to magnetic substances?

Answer 10

attract

Question 11

how can the shape of a magnetic field around a bar magnet be revealed? include safety precautions

Answer 11

put paper on cardboard ontop of two wooden blocks

place the magnet undereneath of the cardboard

place a white peice of paper ontop the carbdoard

sprinkle iron filings over the the paper

tap the paper with a pen to reveal the pattern of the magnetic field

safety: wear goggles, don’t touch the iron filings, put the experiment into a white tray so you don’t spill the iron

Question 12

draw the shape of the magnetic field around a bar magnet

Answer 12

Question 13

what is a magnetic field?

Answer 13

an area around a magnetic material or the moving electric charge through which the force of magnetism acts

Question 14

what are magnetically hard substances?

Answer 14

substances that can be permanently magnetised

difficult to magnetise and demagnetise

these are often alloys of iron, nickel and cobalt

e.g. steel

Question 15

what are magnetically soft substances?

Answer 15

substances that can only be temporarily magnetised - cannot retain their magnetic properties

easy to magnetise and demagnetise

e.g. pure iron

Question 16

what are magnetically hard substances used for?

Answer 16

to make permanent magnets

Question 17

what are magnetically soft substances used for?

Answer 17

to make temporary magnets

Question 18

what test would you perform to discover whether a metal bar is a magnet or not?

Answer 18

it will repel a known magnet

Question 19

you are asked to sort a large pile of empty cans from one another

some are food cans (made of iron)

some are drinks cans (made of aluminium)

how would you go about doing this without looking at the labels?

Answer 19

use a magnet

iron is magnetically soft so it will be attracted to the magnet

aluminium is not attracted to the magnet and will be left in the pile

Question 20

you are presented with three painted metal rods which are identical in appearance except that each is labelled with a letter A,B and C. You are told that one is a piece of soft iron, another is brass and the third is a permanent magnet

what tests would you carry out to decide which bar is which?

Answer 20

hold a magnet to the materials

the brass will not move as it is not magnetic

the iron will attract the magnet

the permanent magnet will repel the magnet

Question 21

what does the term ‘magnetic field line’ mean?

Answer 21

‘lines of force’ - lines that show the size and direction of magnetic fields - they always point from North to South magnetic field

Question 22

is magnetism induced in some materials? how?

Answer 22

some materials that are not magnetic can become magneticaly induced when they are close to a magnetic field

after some time they aquire magnetic property

this is because the magnetic field encouraged its electrons to align and form poles

Question 23

what does a uniform magnetic field pattern mean?

Answer 23

the field lines are exactly parallel to each other

Question 24

how do you use two permanent magnets to produce a uniform magnetic field pattern?

Answer 24

by keeping the opposite poles face each other

the region between the poles would establish magnetic field that would be uniform

Question 25

draw the magnetic field lines for two North poles next to each other

Answer 25

Question 26

draw the magnetic field lines for two South poles next to each other

Answer 26

Question 27

which way do the arrows face when drawing magnetic field lines?

Answer 27

north = going away

south = going in

Question 28

draw the magnetic field lines for one North pole and one South pole facing to each other

Answer 28

attracting

Question 29

define ‘magnet’

Answer 29

an object that produces a magnetic field which pulls on other magnetic materials and attracts or repels other objects

Question 30

define ‘pole’

Answer 30

either of the two points of a magnet to and from which the lines of magnetic force are directed

Question 31

The closer the magnet and the magnetic material get, the stronger/weaker the induced magnetism will be

Answer 31

The closer the magnet and the magnetic material get, the stronger the induced magnetism will be

Question 32

what is the relationshpi between the distance between the magnetic field lines, magnetic strength and the force?

Answer 32

the closer the magnetic field lines, the stronger the magnetic field strength and the forces