Gcse Aqa Physics (Ethan Whorlow)

Front 1

The particles that make up a wave _______ (vibrate) about a fixed point

Back 1

Oscillate

Front 2

In a longitudinal wave, e.g sound wave, the oscillations are ______ to the direction of energy transfer.

Back 2

Parallel

Front 3

What is Frequency?

Back 3

Frequency - number of waves passing a fixed point per second, measure in Hz

Front 4

What is Amplitude?

Back 4

Amplitude - The maximum displacement that any particle achieves from it a undisturbed position in metres (m)

Front 5

What is Wavelength?

Back 5

Wavelength - The distance from on point on a wave to the equivalent point on the next wave in metres (m)

Front 6

What is a Period?

Back 6

Period - The time taken for one complete oscillation in secound (s)

Front 7

What is the movement of a transverse wave?

Back 7

Up and down

Front 8

What is the movement in a longitudinal wave?

Back 8

It compresses

Front 9

How do you calculate the Period?

Back 9

Period = 1 ÷ Frequency

T = 1 ÷ f

Front 10

How do you calculate wave speed?

Back 10

Wave speed =

Frequency x Wavelength

Front 11

Electromagnetic Waves are what type of Waves?

Back 11

Transverse

Front 12

What is the movement of refraction dependent upon?

Back 12

- The angle at which the wave hits the boundary

- The materials involved

Front 13

For light rays, the way in which material affects refraction is called what?

Back 13

Refractive Index

Front 14

From a material with a low refractive index to one with a high refractive index, it bends ______________

Back 14

Towards the normal

Front 15

From a material with a high refractive index to one with a lower refractive index, it bends ____________

Back 15

Bends away form the normal

Front 16

What are Radio Waves?

Back 16

Uses - Television, radio and bluetooth

Radio Waves are low energy waves and, therefore, not harmful, making them ideal for radio transmission.

Front 17

What are Microwaves?

Back 17

Uses - Satellite communications and cooking food

Microwaves travel in a straight line through the atmosphere. This makes them ideal for transmitting signals to satellites in orbit and transmitting them back down to receivers.

Front 18

What are Infrared waves?

Back 18

Uses - Electrical heaters, Cooking food and infrared cameras.

Electrical heaters, grills and toasters glow red as the electricity flows through them. This transmits infrared energy that is absorbed by the food and converted back into heat.

Front 19

What is visible light?

Back 19

Uses- Fibre optic communications.

Visible light travels down optical fibres from one end to the other without being lost through the sides.

Front 20

What are Ultraviolet Waves?

Back 20

Uses - Energy efficient bulbs, security marking and sunbeds.

In energy efficient light bulbs, UV waves are produced by the gas in the bulb when it is excited by the electric current. These UV waves are absorbed by coating the bulb, which fluoresces giving of visible light.

Front 21

What are X-ray waves?

Back 21

Uses - Medical imaging and treatments.

X-rays are able to penetrate soft tissue but not bone. A photographic plate behind a person will show shadows where bones are.

Front 22

What are Gamma Rays?

Back 22

Uses - Sterilizing food, treatment of tumours

Gamma rays are the most energetic of all electromagnetic waves and can be used to destroy bacteria and tumours.

Front 23

What are hazards of Electromagnetic Waves?

Back 23

Ultraviolet waves can make skin age prematurely and increase the risk of skin cancer.

X-rays and gamma rays are ionizing and can damage cells and can cause cancer.

Front 24

What is Electric current?

Back 24

Electric current is the flow of electrical charge - the greater the rate of flow, the higher the current.

Front 25

How is Current measured?

Back 25

Current is measured in amperes (A), which is often abbreviated to amps, using a ammeter.

Front 26

How is Electric charge calculated?

Back 26

Electric charge is measured in coulombs (C) and can be calculated with the equation:

Charge flow = Current × Time.

Q = It

Front 27

As the current in a single, closed loop of s circuit has nowhere else to go the current is the ________________.

Back 27

The same at all points in the loop.

Front 28

The higher the resistance

Back 28

- The more difficult it is for charge flow

- The lower the current

Front 29

What is resistance measured in?

Back 29

Ohms

Front 30

What is potential difference?

Back 30

Potential difference (voltage) tells us the difference in electrical potential energy from one point in the circuit to another.

Front 31

The bigger the potential difference

Back 31

- The greater the flow charge though the component

- The bigger the current

Front 32

How is potential difference measured?

Back 32

Potential difference is measured in volts (V) using a voltmeter.

Potential difference, current and resistance are linked by the equation:

Potential difference =

Current × Resistance

V=IR

Front 33

Resistors

Back 33

- An ohmic conductor is a resistor which the current is directly proportional to the potential difference at a constant temperature

- This means that the resistance remains constant as the current changes.

- It is indicated by a linear (straight line) graph

Front 34

Filament Lamp

Back 34

- As the current through a filament lamp increases, it's temperature increases

- This causes the resistance to increase as the current increases

- It is indicated by a curved graph

Front 35

Diodes

Back 35

- The current through a diode will only flow in one direction

- The diode has a very high resistance in the reverse direction.

- This is indicated by the horizontal line along the x axis, which shows that no current flows.

Front 36

Thermistors

Back 36

- The resitance of a thermistor decreases as the temperature increases.

- This makes then useful in circuits where temperature control or response is required

- For example, a thermistor could be used in a circuit for a thermostat that turns a heater off at a particular temperature is and indicator light that turns on when a system is overheating.

Front 37

Light Dependent Resistors (LDRs)

Back 37

- There resistance of an LDR decreases as light temperature intensity increases.

- This makes them useful where automatic light control or detection is needed, e.g. in dusk till dawn garden lights / street lights and in cameras / phones to determine if a flash is needed

Front 38

Series Circuit

Back 38

- There is the same current through each component.

- The total potential difference of the power supply is shared between components.

- The total resistance of two components is the sum of the resistance of each component. This is because the current has to travel through each component in turn

-Adding resistors in series increases the total resistance (R) In ohms.

Front 39

Parallel Circuit

Back 39

- The potential difference across each component is the same

- The total current drawn from the power supply is the sum of the currents through the separate components

- The total resistance of two resistors is less than the resistance of the smallest individual resistor.

Front 40

Word equation for weight

Back 40

Weight = mass × gravitational field strength

Front 41

Work done

Back 41

Work done = force × distance (along the line action of the force)

Front 42

Force applied to a spring

Back 42

Force applied to a spring = spring constant × extension

Front 43

Distance travelled

Back 43

Distance travelled = speed × Time

Front 44

Kinetic energy

Back 44

Kinetic energy = 0.5 × mass × speed^2

Front 45

Gravitational potential energy

Back 45

Gravitational potential energy = mass × gravitational field strength × height

Front 46

Power

Back 46

Power = Energy transferred ÷ time

Front 47

Power

Back 47

Power = work done ÷ time

Front 48

Efficiency

Back 48

Efficiency =useful output energy transfer ÷ total input energy transfer

Front 49

Efficiency

Back 49

Efficiency = useful power output ÷ total power input