Science - Physics - Magnets

Front 1

What is magnetism?

Back 1

A a non-contact force. Magnets attract magnetic materials. Iron, nickel and cobalt are magnetic materials.

Front 2

What are alloys?

Back 2

All mixtures of metals.

Front 3

What is magnetisation?

Back 3

When you make a magnet from a piece of iron or steel.

Front 4

What is a magnetic field?

Back 4

A region where magnetic materials experience a force.

Front 5

How can you draw a magnetic field?

Back 5

By using magnetic field lines. They always point from North to South.

Front 6

How can you investigate magnetic field lines?

Back 6

With iron fillings (that align along the field lines) or a plotting compass (which will always point from North to South along the field lines).

Front 7

What does the Earth have and what affect does this have on compasses?

Back 7

The Earth has a magnetic field, and a compass is a small magnet that always point North, following the Earth's magnetic field. But magnetic materials placed near a compass can change the direction it points.

Front 8

What can magnets be used for?

Back 8

Magnets can be used to sort cans for recycling, to hold fridge doors shut, and in compasses that sailors or walkers use.

Front 9

What is the difference between bar magnets and electromagnets?

Back 9

Bar magnets stay magnetic all the time, however electromagnets can be turned on or off.

Front 10

What is a current?

Back 10

A current is the flow of electricity and flows when an electric charge moves around a circuit.

Front 11

How can you make electro magnets stronger?

Back 11

By increasing the amount of coils in the wire, by increasing the size of the current (the voltage), using an iron core (but soft iron has to be used as if something else ((like a steel core)) was used, it would remain magnetized even after the current was switched off.

Front 12

What can electromagnets be used for?

Back 12

They can be used for lifting things, and they are also used in electrical bells, relays, and and video and music recording

Front 13

What is a reed switch?

Back 13

A reed switch has two thin pieces of iron in it. If a magnet is held near the switch, the pieces of iron are magnetised and touch each other.

Front 14

What are relays used for? Give an example.

Back 14

Relays are often used to make things safer. For example, the starter motor in a car uses a high current and needs thick wires for the current to flow through. A relay is used in a car so that the driver does not have to touch any part of the circuit that has a high current.

Front 15

What is an electric motor made out of?

Back 15

A loop of coiled wire in a magnetic field.

Front 16

What is sound and how is sound made?

Back 16

Sound is a form of energy and sounds are made when things vibrate.

Front 17

What happens when sound is produced?

Back 17

Air molecules move backwards and forwards and produces a sound wave. However, sound needs a substance or particles to pass on the vibration, so it cannot travel through a vacuum is there are no air molecules to vibrate.

Front 18

How fast does sound travel (solid, liquid, gas)?

Back 18

Sound travels the fastest in solids, second fastest in liquids and slowest in gases. This is because the particles in a solid are closer together so the vibration is passed along quicker.

Front 19

Sound vs Light. Who wins and why?

Back 19

Light travels faster than sound, as light travels at 3 million miles per second, nearly a million times faster than sound. Sound travels at 340 miles per second. Light travels faster than sound, because sound needs particles to travel through, unlike light.

Front 20

What is an oscilloscope?

Back 20

An oscilloscope shows wave patterns and allows us to see sound.

Front 21

What is frequency, how do you see it on a oscilloscope and what is it measured in?

Back 21

How high/ low the sound is (high/low pitch). How close the waves are/how many waves there are. Hertz (hz).

Front 22

What is the loudness of a sound, what does it look like on an oscilloscope and what is it measured in?

Back 22

The louden the sound, the larger the waves On an oscilloscope trace, the loudness of the sound is shown by the height of the wave. This is called the amplitude. Decibels.

Front 23

What is the wavelength?

Back 23

The distance between two waves.

Front 24

What is amplitude?

Back 24

The size of the waves.

Front 25

What is the top of a wave and what is the bottom?

Back 25

Top = Peak. Bottom = Trough.

Front 26

How can you calculate the speed of which sound is travelling at?

Back 26

D, S, T.

Speed = D ÷ T

Distance = S × T

Time = D ÷ S

Front 27

Explain how sound travels through your ear.

Back 27

1) Sound waves are collected by the ear lobe (pinna).

2) The waves travel along your ear canal.

3) The waves make the eardrum vibrate.

4) The smallbones (ossicles) amplify the vibrations.

5) The cochlea turns these into electrical signals.

6) The auditory nerve takes the signals to the brain.

Front 28

Explain the process of the stages sound into the ear.

Back 28

Sound waves travel through the air and into the ear. They cause the eardrum to vibrate. The vibrations are passed onto the cochlea in the inner ear, where they are changed to electrical signals called impulses. A nerve takes this message to the brain. When the message reaches the brain, we hear sound.

Front 29

How can we measure how loud a sound is?

Back 29

By using an intensity metre, which is an instrument which measures the loudness of a sound in decibels. The threshold of hearing is the quietest sound we can hear.

Front 30

What can soft materials do?

Back 30

Absorb sound, therefore are used in soundproofing and in ear protectors.