magmetism (topic 7)

Question 1

describe how a student could identify the shape of a magnetic field around a bar magnet (3)

Answer 1

• place magnet under a piece of paper
• sprinkle iron filings on paper
• tap paper to evenly distribute iron filings and align them with the magnetic field

Question 2

Answer 2

Question 3

which of the following is a magnetic material:
- wood
- iron
- gold
- aluminium

Answer 3

iron

Question 4

the student says the magnet is strongest along the long edge of the magnet because it has the largest surface area, explain why the student is wrong (2)

Answer 4

• the magnetic field strength is strongest where the field lines are closes together
• field lines are closest together at the poles
• field is strongest at the poles

Question 5

describe a method that the student could follow to test the strength of the pole compared to the side of the magnet (3)

Answer 5

• use of small metallic object such as a paper clip, pin
• attach 1 pin at a time to the side of the magnet until the magnet cannot pick up any more
• record the number of objects attached
• repeat for the pole of the magnet

Question 6

describe how the student could produce a uniform magnetic field (1)

Answer 6

place the north pole of one magnet near to the south pole of another magnet

Question 7

Answer 7

Question 7

a student rubs the pole of the magnet up and down the iron nail for 1 minute, the student then uses the nail to attempt to pick up a small metallic pin, explain why the nail did not pick up the pin (1)

Answer 7

• the student did not align the magnetic domains in the same direction
• the student needed to continuously rub the magnet along the nail in the same direction

Question 8

the direction of magnetic field lines for a magnet is always from

Answer 8

north to south

Question 9

state where the magnetic field is strongest around a bar magnet

Answer 9

at the poles of the magnet

Question 10

explain why the suspended magnet spins when a magnet is nearby (4)

Answer 10

• the magnetic field of the labelled bar magnet interacts with the magnetic field of the unlabelled magnet
• causing a force to be exerted on the magnets
• repulsive force when the poles are the same
• attractive force when the poles are opposite

Question 11

the student brings an iron bar close to the suspended magnet, the magnet rotates towards the metal bar, explain what happens when the student turns the iron bar around so the other end faces the magnet (2)

Answer 11

• no change
• the magnet is still attracted to the metal bar and will turn towards it

Question 12

Answer 12