Physics As Level Aqa

Front 1

Electromagnetic exchange particle

Back 1

Photon

Front 2

Strong nuclear force exchange particle

Back 2

Pions

Front 3

Gravity exchange particle

Back 3

Graviton

Front 4

Electromotive force

Back 4

Electrical energy per unit charge produced by the source.

Front 5

Internal resistance

Back 5

The opposition to the flow of charge through the source.

Front 6

Potential difference

Back 6

The work done (or energy transfer) per unit charge.

Front 7

Resistance

Back 7

The opposition to the flow of charge. Caused by collisions between the charge carriers.

Front 8

Ohm's law.

Back 8

The Pd across a metallic conductor is proportional to the current through it, provided that the physical condition does not change.

Front 9

Resistivity

Back 9

The measure of resistance per unit volume of a material.

Front 10

What is the critical temperature of a superconductor?

Back 10

The temperature at which below resistance is zero.

Front 11

What are superconductors used for?

Back 11

Creating high power magnetic fields, used for mri's and particle accelerators.

Front 12

What does the IV graph of a wire look like?

Back 12

Straight line through the origin.

Front 13

What does the IV graph of a filament lamp look like?

Back 13

Curved line, decreasing gradient through origin.

Front 14

What does the IV graph of a diode look like.

Back 14

Hardly any conduction in one direction. Steep increase after activation pd.

Front 15

What does the IV graph of a thermistor look like?

Back 15

Straight line through the origin. Shallower gradient at lower temperatures.

Front 16

What does the resistance temperature graph of a NTC thermistor look like?

Back 16

A curved line that goes from a negative gradient to a more neutral one.

Front 17

When is the strong nuclear force effective?

Back 17

Repulsive when less than 0.5 fm attractivee between 0.5 and 5fm no effect at lengths greater than that.

Front 18

Calculating uncertainty using range.

Back 18

Find the range and divide it by two, divide the half range by the mean, times by 100 if it asks for percentage uncertainty.

Front 19

Longitudinal wave properties.

Back 19

Direction of vibration of particles is parallel to the direction the wave travels.

Front 20

Transverse wave properties

Back 20

The direction of vibration is perpendicular to the direction of the wave travels.

Front 21

Which seismic waves are longitudinal or transverse.

Back 21

P waves longitudinal.

S waves are tran s ver s e

Front 22

dSin(©)=n^. Equation for diffraction grating.

Back 22

d is the distance between slits. Calculated by 1/number of slits per metre.

n is the number of orders.

Front 23

W=pi*d/s. Double slit fringe spacing.

Back 23

W is the fringe spacing.

D is the slit screen distance.

S is the split separation.

Front 24

What factors are required for two waves to be coherent?

Back 24

Same phase difference, and frequency.

Front 25

What does the stress strain graph look like.

Back 25

It looks like this.

P is the limit of proportionality.

E is the elastic limit.

Y is the yield point

UTS is the ultimate tensile stress.

B is the breaking point.

Front 26

Elastic and inelastic collisions.

Back 26

Elastic has no loss of kinetic energy, momentum is also conserved.

Inelastic collisions loss of kinetic energy, some is transferred to heat. Momentum is conserved.

Front 27

Define the term moment.

Back 27

The turning force around an object. Defined as the force * perpendicular distance from pivot.

Front 28

Modal dispersion.

Back 28

Where a pulse of light spreads out in a fibre optic cable due to the different distances travelled by the ray of light.

This can be prevented by using a thinner optical fibre.

Front 29

Cladding is needed around the core because?

Back 29

Light from different fibres would cross over.

Front 30

First harmonic frequency equation.

Back 30

F=c/wavelength or F=c/2l

For the second harmonic f=c/l

For the third harmonic F=3c/2l

Front 31

What shows the particle nature of waves?

Back 31

The photoelectric effect.

Front 32

What shows the wave nature of particles?

Back 32

Particle diffraction.

To find the wavelength of a particle use the de Broglie equation.

Front 33

Wavelength of a microwave?

Back 33

3cm

Front 34

What is shown on an emission spectrum?

Back 34

Coloured lines on a black background. These lines refer to specific frequencies of photons which represent specific quanta of energy that cause the excitation of an atoms electrons.

Front 35

What does an absorption spectra show?

Back 35

Black lines on a rainbow background. This represents specific frequencies of photons which represents specific quanta of energy that the atoms electrons absorb to become excited.

Front 36

How does fluorescent tubes work?

Back 36

1. Mercury in a tube with a high pd across it. The charge carrying electrons bump into the mercury's electrons exciting them.

2. These electrons then deexcite producing ultraviolet photons. These are absorbed by the fluorescent coating of the tube causing the electrons to excite.

3. These electrons deexcite in steps causing multiple frequency photons of visible light to be emitted by the tube.

Front 37

What factors show that something is a weak interaction?

Back 37

Quark flavour change.

Leptons are involved.

Neutrinos are involved.

Front 38

What is electron capture?

Back 38

When a proton absorbs electron, causing a neutrino and a neutron to be produced.

Front 39

What happens in annihilation?

Back 39

A particle and antiparticle collide, this produces two photons in opposite directions which conserves energy and momentum.

Front 40

What happens in pair production?

Back 40

A high energy photon, passing a nucleus, turns into an antiparticle and particle. These travel in opposite directions to conserve momentum.