topic 12

Question 1

a student has a bar magnet, a piece of iron the same size as the magnet and some paper clips.
describe how the student could use these items to demonstrate temporary induced magnetism

Answer 1

use magnet to pick up one paper clip and use this first paper clip to pick up another. remove magnet and paper clips and they are no longer attracted

Question 2

figure 9 apparatus w solenoid spring and iron nail. when the current in the solenoid is switched on the solenoid attracts the iron nail.

describe how the student could use this apparatus to investigate how the size of the current in the solenoid affects the force of attraction between the solenoid and the iron nail

Answer 2

measure length of the spring before current switched on. use an ammeter to ensure the current. calculate the extension of the spring and repeat this with different currents

Question 3

a student uses a plotting compass to investigate the magnetic field around a wire figure 10 showing wire going straight through a card.

describe how the student could develop the experiment to find the shape of the magnetic field produced by the current

Answer 3

use a compass to record field at one location and find how the field continues. connect the dots to reveal shape of the field

Question 4

a student uses a plotting compass to investigate the magnetic field around a wire figure 10 showing wire going straight through a card.

which one shows possible direction of compass needle when there is a current in the wire going from P to Q?

A) arrow to right
B) arrow to south west
C) arrow to north west
D) arrow to up

Answer 4

A) arrow to right

Question 5

the direction of the force due to the magnetic field is

A) down
B) up
C) towards the north pole of the magnet
D) towards the south pole of the magnet

Answer 5

B) up

Question 6

the interaction between the magnetic fields produced by the magnet and the current in the wire produces forces on the magnet and the wire. compare these two forces

Answer 6

forces are equal and opposite

Question 7

figur 11 shows magnetic field of a magnet
at which point is the magnetic field the strongest

A)
B)
C)
D)

Answer 7

B

Question 8

describe how flemings left hand rule can be used determine the direction of the force acting on the roller

Answer 8

first finger, second finger and thumb held mutually perpendicular. first finger in direction of magnetic field and thumb in direction of force

Question 9

draw an arrow to show the direction of the force acting on the roller

Answer 9

upwards arrow