Physics Test unit 4

Question 1

Magnets have two poles: a north and a south

Question 2

Like poles repel (push each other apart)

Answer 2

• A north pole will repel a north pole

-A south pole will repel a south pole

Question 3

Opposite poles attract (are pulled toward each other)

Answer 3

A north pole will be attracted to a south pole

Question 4

The magnetic metals are:

Answer 4

-iron
-Cobalt
-Nickel
-Steel

Question 5

Magnetic materials

Answer 5

will always be attracted to the magnet, regardless of which pole is held close to it

Question 6

two types of magnets:

Answer 6

-Permanent magnets
-induced magnets

Question 7

Permanent magnets

Answer 7

-A permanent magnet will produce its magnetic field

*It will not lose its magnetism

Question 8

Use of Permanent magnets

Answer 8

-compass
-Motor
-generator

Question 9

Induced magnets

Answer 9

-An induced magnet is a material that temporarily becomes magnetic when near a magnet, attracting the magnet with opposite poles at the closest ends

• When removed from the magnetic field, the material will lose its induced magnetism quickly and become unmagnetised

Question 10

Iron is a soft magnetic material that is easy to magnetize and demagnetise.

Question 11

A magnetic field

Answer 11

A region in which a magnetic pole experiences a force

Question 12

-The magnetic field is strongest at the poles

• Therefore, the magnetic field lines are closer together at the ends of the magnets

Question 13

-The magnetic field becomes weaker as the distance from the magnet increases

-Therefore, the magnetic field lines get further apart

Question 14

Magnetic field lines

Answer 14

• field lines always have an arrow indicating the direction of the field line

-The direction of the field line shows the direction that the magnetic force would act

Question 15

Magnetic field strength

Answer 15

-the strength of the magnetic field is shown by the spacing of the magnetic field lines

-If the magnetic field lines are close together then the magnetic field will be strong

-If the magnetic field lines are far apart then the magnetic field will be weak

Question 16

Plotting magnetic field lines

Answer 16

-Use iron fillings
- Use a compass

Question 17

Using iron filings

Answer 17

1.)Place a piece of paper on top of the magnet

2.)Gently sprinkle iron filings on top of the paper

3.)Now carefully tap the paper to allow the iron filings to settle on the field lines

Question 18

Using compasses

Answer 18

1.) Place a magnet on paper.
2.) Mark a dot near one corner of the magnet.
3.) place a compass by the dot, aligning the needle with it.
4.) Mark a new dot where the needle points.
5.) Move the compass to the new dot and repeat
6.) Continue until dots form a path from one end of the magnet to the other.
7.) Connect the dots with a smooth curve this is a magnetic field line.
8.) Field lines go from the magnet’s north to south pole, matching the compass needle’s direction.
9.) Repeat the process to create other magnetic field lines around the bar magnet

Question 19

-when a compass needle is close to a magnet, it will point in the direction of the of the magnetic field lines

-this goes from north to South Pole