Magnets

Question 1

What are the magnetic materials?

Answer 1

Iron, steel, nickel, and cobalt.

Question 2

What is a magnetic field?

Answer 2

An invisible area around a magnet where magnetic forces can be felt.

Question 3

What are the poles of a magnet?

Answer 3

North and South — unlike poles attract, like poles repel.

Question 4

What happens when you cut a magnet in half?

Answer 4

You get two smaller magnets, each with a north and south pole.

Question 5

What is an electromagnet?

Answer 5

An electromagnet is created by an electric current flowing through a wire around a core (usually iron).

Question 6

What is magnetic induction?

Answer 6

When a magnetic material becomes a magnet after being placed in a magnetic field.

Question 7

What is a magnetic domain?

Answer 7

A region in a material where the magnetic moments of atoms are aligned.

Question 8

What happens to magnetic domains in an unmagnetized object?

Answer 8

They are randomly arranged, cancelling each other out.

Question 9

What happens when you heat a magnet?

Answer 9

It can lose its magnetism as the atoms get too jiggly and misaligned.

Question 10

Why does the Earth act like a big magnet?

Answer 10

Because molten iron moves in its outer core, a magnetic field is generated.

This refers to the Earth’s magnetic field and its properties.

Question 11

What device shows the direction of a magnetic field?

Answer 11

A (plotting) compass.

Question 12

What is the area around a magnet where the force is strongest?

Answer 12

At the poles (where the field lines are closest).

Question 13

Why do we use electromagnets in scrapyards?

Answer 13

They can be turned on and off to move magnetic materials like steel. They can also be used to pick out magnets from non-magnets

Question 14

What’s a use for magnets in everyday electronics?

Answer 14

In speakers and headphones (they help create sound).

Question 15

What is a bar magnet?

Answer 15

A permanent magnet shaped like a bar with north and south poles at each end.

Question 16

What does a compass show?

Answer 16

A magnetic north & south pole

Question 17

What happens when two like poles come together?

Answer 17

They repel each other

Question 18

What happens when two unlike poles come together?

Answer 18

They attract each other

Question 19

What is an electrical current?

Answer 19

The flow of electricity through an electrical circuit

Question 20

What is the purpose of an electrical current?

Answer 20

To give power and perform tasks such as turning on a lightbulb

Question 21

What are the characteristics of magnets?

Answer 21

Attracted to ferromagnetic materials, (weakly to paramagnetic) & repelled weakly by diamagnetic

Question 22

What components make up an electromagnet?

Answer 22

A coil of wire (solenoid), current, and a core

Question 23

What material is commonly used for the coil in an electromagnet?

Answer 23

Copper

Question 24

What role does current play in an electromagnet?

Answer 24

It flows through the wire and lines up the domains

Question 25

What does the current create around the coiled wire?

Answer 25

A magnetic field

Question 26

How does an electromagnet differ from a bar magnet?

Answer 26

An electromagnet is a non-permanent magnet that can be switched on and off

Question 27

Fill in the blank: An electromagnet consists of a coil of wire (solenoid) carrying a current through a _______.

Answer 27

core

Question 28

What is the relationship between the geographical and magnetic north & south poles?

Answer 28

The geographical north pole is the magnetic south pole and vice versa. ## Footnote The reason for this is because a compass points towards geographical north, therefore it is attracted to magnetic south.

Question 29

What do a magnet and a plotting compass have in common?

Answer 29

Both have north-seeking poles ## Footnote This indicates that they both orient themselves in relation to the Earth's magnetic field.

Question 30

What color indicates the north-seeking pole of a compass?

Answer 30

Red ## Footnote The red end of the compass needle points towards the magnetic north.

Question 31

What color indicates the south-seeking pole of a compasss?

Answer 31

White ## Footnote The white end of the compass needle points towards the magnetic south.

Question 32

What does a compass point towards when placed next to a magnet?

Answer 32

The compass will only point towards the way in which the magnetic field lines do ## Footnote This indicates the influence of magnetic fields on nearby objects.

Question 33

What type of charge do every electron and proton possess?

Answer 33

An electric charge ## Footnote Electrons have a negative charge while protons have a positive charge.

Question 34

Why is chromium considered anti-magnetic?

Answer 34

Chromium's domains will line up to be magnetic when its warm and to not be magnetic when its cold, and its takes up less energy when its not magnetic ## Footnote This property affects its magnetic characteristics.

Question 35

What is located at the center of all atoms?

Answer 35

Protons and neutrons

Question 36

What happens to the magnetic properties of atoms with too many or too few electrons?

Answer 36

They aren't magnetic ## Footnote The balance of electrons and protons is crucial for magnetic properties.

Question 37

What are valence electrons?

Answer 37

Electrons that are outside the shell of the atoms ## Footnote Valence electrons play a key role in chemical bonding and reactions.

Question 38

True or False: Every electron is a tiny magnet of itself.

Answer 38

True ## Footnote This property contributes to the overall magnetic properties of materials.

Question 39

What are the labels used for the poles of a bar magnet?

Answer 39

N & S Poles ## Footnote N stands for North pole and S stands for South pole.

Question 40

What does the diagram of a bar magnet show?

Answer 40

The field pattern around a bar magnet ## Footnote The field lines indicate the direction and strength of the magnetic field.

Question 41

Fill in the blank: The magnetic field is ____ at the center of a bar magnet.

Answer 41

weak ## Footnote The field strength is stronger near the poles and weaker at the center.

Question 42

True or False: The magnetic field lines around a bar magnet are always closed loops.

Answer 42

True ## Footnote Magnetic field lines exit from the North pole and enter the South pole, forming closed loops.

Question 43

What are superconductors known for?

Answer 43

Zero electrical resistance and amazing magnetic properties ## Footnote Superconductors carry electricity without losing energy and show special magnetic effects like the Meissner effect.

Question 44

What is the phenomenon of zero electrical resistance in superconductors?

Answer 44

The ability to conduct electricity without any loss of energy ## Footnote This occurs below a certain critical temperature specific to each superconductor.

Question 45

What remarkable magnetic property do superconductors exhibit?

Answer 45

The Meissner effect ## Footnote This effect causes a superconductor to repel magnetic fields, leading to magnetic levitation.