Term	Definition
absolute refractive index	the absolute refractive index (or just the refractive index), n , of a medium is the ratio of the speed of light in a vacuum to the speed of light in the material. (also the ratio of the wavelength of light in a vacuum to the wavelength of light in the medium)
angle of incidence	the angle between the incident ray and the normal.
angle of refraction	the angle between the refracted ray and the normal.
atomic mass units (u)	by definition one twelfth of the mass of a carbon-12 nucleus.
atomic number	the number of protons in an atomic nucleus. It is this number that determines the element and its properties.
binding energy	the energy needed to split a nucleus into its separate nucleons (not on the CfE Higher course)
chain reaction	when a nucleus undergoes fission it releases neutrons that can go on to cause further fission reactions by interactions with other nuclei. If there is a sufficient concentration of suitable nuclei, the process becomes self-sustaining.
coherent waves	coherent waves are waves that have the same frequency, speed and have a constant phase relationship.
collimator	part of a spectrometer that is used to produce a parallel beam of light.
constructive interference	when waves arrive at a point in phase or crest meets a crest and trough meets a trough resulting in a wave of larger amplitude than the individual waves.
critical angle	the angle above which total internal reflections occurs. Or, the maximum value of the angle between the normal and the ray in glass, θ glass, for which refraction can occur.
destructive interference	when waves arrive at a point in out of phase or crest meets a trough resulting in a wave of smaller amplitudeas the waves cancel out.
diffraction	an effect that causes waves to bend as they go past the end of an obstacle or through a small gap in a barrier.
dispersion	the process of splitting up light into its constituent colours, this can be done with a prism and white light.
electromagnetic waves	the spectrum of waves that includes radio, visible light, X-rays etc which all have no mass and travel at the speed of light in a vacuum.
excited state	any atomic energy level higher than the ground state.
ferromagnetic	materials in which the magnetic fields of the atoms line up parallel to each other in regions known as magnetic domains.
fission	the splitting of a large atomic nucleus into smaller fragments, with the resultant release of excess energy.
gold leaf electroscope	device used to measure small amounts of charge.
grating	a transparent slide of glass or plastic that has a very large number of equally spaced grooves machined on to its surface. Each groove acts as a source for coherent beams of light.
ground state	the lowest energy level of an atom where an electron has the lowest energy level.
induced fission	the deliberate splitting of a large nucleus caused by the collision of the nucleus with a neutron.
interference	a phenomenon in which two waves superpose to form a resultant wave of greater, lower, or the same amplitude.
ionisation level	the energy level at which an electron can break free from an atom.
irradiance	the power per unit area of radiation incident on a surface.
isotopes	different forms of the same element. The isotopes of an element contain the same number of protons but have different numbers of neutrons. (Many isotopes are unstable and can emit nuclear radiation)
line absorption spectrum	a spectrum that consists of narrow dark lines across an otherwise continuous spectrum.
line emission spectrum	a spectrum consisting of narrow lines of light, the position of which depend on the substances producing the light.
magnetic domains	regions in a ferromagnetic material where the atoms are aligned with their magnetic fields parallel to each other.
magnetic field	a magnetic field is a region in which a moving charge experiences a magnetic force.
magnetic poles	one way of describing the magnetic effect, especially with permanent magnets. There are two types of magnetic poles - north and south. Opposite poles attract, like poles repel.
mass defect (do not confuse with mass difference)	the difference between the mass of a nucleus and the total mass of an equal number of individual nucleons.
mass difference	the difference in mass between the reactants and products in a nuclear reaction. The resulting mass difference is converted to energy according to the equation E=mc 2 .
mass number	the total number of nucleons (protons and neutrons) in the nucleus of an atom.
monochromatic	radiation consisting of a single frequency.
monochromatic light	light of one wavelength (and therefore one colour)
normal	a line drawn at right angles to a surface or the boundary between two different media
nucleon	the general term for protons and neutrons (contained in the nucleus).
nuclide	the nuclei of one particular isotope. These nuclei all have the same atomic number and mass number.
path difference	the difference in path lengths of two sets of waves.
phase	denotes the particular point in the cycle of a waveform.
photocathode	the terminal from which electrons will be emitted due to the photoelectric effect.
photoelectric effect	the emission of electrons from a metal due to the effect of electromagnetic radiation.
photoelectrons	free electrons produced by the photoelectric effect
photoemission	the emission of electrons from a material caused by light shining on it.
photon	the particle of electromagnetic radiation.
potential difference	the potential difference between two points is a measure of the work done in moving one coulomb of charge between the two points.
principle of reversibility	the principle of reversibility states that a ray of light will follow the same path in the opposite direction when it is reversed.
prism	a prism is a transparent optical element with flat, polished surfaces that refract light. A dispersive prism can be used to break light up into its constituent spectral colours.
quanta	a "packet" certain amount, often referring to the energy of photons.
radioactive decay series	a chain of radioactive decays as a radioactive element changes to eventually become a stable, non-radioactive element.
radioisotope	short for radioactive isotope.
radionuclide	short for radioactive nuclide.
refraction	refraction occurs when a wave goes from one medium into another. When a wave is refracted, its speed and wavelength change; its frequency remains constant; its direction sometimes changes.
spectrometer	an instrument that can make precise measurements of the spectra produced by different light sources.
spontaneous fission	the random splitting of a large atomic nucleus due to the internal processes within the nucleus. (it does not require neutrons to cause the reaction and so is not of use in a nuclear reactor).
stopping potential	the minimum voltage required to reduce photoelectric current to zero.
telescope	the part of a spectrometer through which the spectrum is viewed.
threshold frequency	the minimum frequency of electromagnetic radiation that will cause photoemission for a particular substance.
total internal reflection	when a ray of light travelling in a more dense substance meets a boundary with a less dense substance at an angle greater than the critical angle, the ray is not refracted but is all reflected inside the more dense substance.
turntable	the stage or platform of a spectrometer on which the grating or prism sits. The turntable has an angular scale on it to allow measurements to be made.
work function	the minimum energy required to cause photoemission from a substance.

WORKSHOP

WORKSHOP for HIGHER 2019-

https://www.sqa.org.uk/sqa/files_ccc/ExamTimetable2018.pdf

Create your own SQA timetable when you click on the link below https://www.sqa.org.uk/sqa/41619.2558.html

Here are a few little gems that we will discuss at the workshop. If you can’t make it then you ought to be able to work through the material yourself. I hope you find this material useful. I will stick up the agenda as soon as. I will also publish a sheet on the question grid against past papers. Best wishes for your revision

HIGHER WORKSHOP from CfE 2019 word Download

The word document. Lots to digest here, so you might want to look over it prior to the workshop. Don’t do it all as I’ll have nothing to go through with you for the workshop.

HIGHER WORKSHOP from CfE 2019 pdf Download

Please note the workshop is not a place for you to learn, but a place for you to get practice and a few exam techniques!

Sketch Graphs pptx power point Download

A power point document for sketching graphs in physics

Sketch Graphs worksheet word Download

The above is a worksheet that fits with the sketch graph power point

Higher Revision Cards A4

Higher Revision Cards

Must Justify

H Multiple Choice

Past Paper Q revision ODU

Past Paper Q revision P&W

Semiconductors

For some of you this first link will help explain about semiconductors, for others it will freak you out. If you are someone who likes to know and understand the background behind your Physics, then this video will help in your understanding. If you just like to accept what you’ve been taught then maybe give it a wide berth! It explains where these energy gaps come from, what is means to be a semi-conductor. The SSERC meet mentions the words “quantum tunnelling” which appears in AH Physics. If keeping up with the basics is enough then use the hour for more useful revision. I am 29 mins in, and it has taken my 40 mins, but it is very informative.

https://m.youtube.com/watch?v=uxUZvJ4F7_U

Remind you of anyone?

This has now become a topic that is not really enjoyed by most Higher candidates. Here is an intro video to help you out.

https://ocw.mit.edu/courses/mechanical-engineering/2-627-fundamentals-of-photovoltaics-fall-2013/lecture-videos-slides/2011-lecture-5-charge-separation-part-i/

More definitions courtesy of

https://quizlet.com/90855867/122-conductors-semiconductors-and-insulators-flash-cards/

Glossary for Revision
https://quizlet.com/90855867/122-conductors-semiconductors-and-insulators-flash-cards/
Conductors	Conductivity is the ability of a materials to conduct charge carriers (electrons or positive holes) (all metals, semi metals like carbon-graphite, antimony and arsenic)
Insulators	Materials that have very few charge carriers (free electrons or positive holes). (plastic, glass and wood)
Semiconductors	These materials lie between the extremes of good conductors and good insulators. They are crystalline materials that are insulators when pure but will conduct when an impurity is added and/or in response to light, heat, voltage, etc (silicon (Si), germanium (Ge), gallium arsenide (GaAs)
Band structure	Electrons in an isolated atom occupy discrete energy levels. When atoms are close to each other these electrons can use the energy levels of their neighbours. When the atoms are all regularly arranged in a crystal lattice of a solid, the energy levels become grouped together in a band. This is a continuous range of allowed energies rather than a single level. There will also be groups of energies that are not allowed, what is known as a band gap. Similar to the energy levels of an individual atom, the electrons will fill the lower bands first. The fermi level gives a rough idea of which levels electrons will generally fill up to, but there will always be some electrons with individual energies above this
In a conductor:	the highest occupied band, known as the conduction band, is not completely full. This allows the electrons to move in and out from neighbouring atoms and therefore conduct easily
In an insulator:	the highest occupied band is full. This is called the valnce band, by analogy with the valence electrons of an individual atom. The first unfilled band above the valence band above the valence band is the conduction band. For an insulator the gap between the valence and conduction bands is large and at room temperature there is not enough energy available to move electrons from the valence band into the conduction band, where they would be able to contribute to conduction. Normally, there is almost no electrical conduction in an insulator. If the applied voltage is high enough (beyond the breakdown voltage) sufficient electrons can be lifted to the conduction band to allow current to flow. Often this flow of current causes permanent damage. Within a gas this voltage is often referred to as the striking voltage, particularly within the context of a fluorescent lamp since this is the voltage at which the gas will start to conduct and the lamp will light.
In a semiconductor:	the gap between the valence band and the conduction band is smaller, and at room temperature there is sufficient energy available to move some electrons from the valence band into the conduction band, allowing some conduction to take place. An increase in temperature increases the conductivity of the semiconductor as more electrons have enough energy to make the jump to the conduction band. This is the basis of an NTC thermistor. NTC stands for “negative temperature coefficient” (increased temperature means reduced resistance). This makes current increase so conductivity increases.
Optical properties of materials	Electron bands also control the optical properties of materials. They explain why a hot solid can emit a continuous spectrum rather than a discrete spectrum as emitted by a hot gas. In the solid the atoms are close enough together to form continuous bands. The exact energies available in these bands also control at which frequencies a material will absorb or transmit and therefore what colour will appear
Bonding in semiconductors	The most commonly used semiconductors are silicon and germanium. Both these materials have a valency of 4 (they have 4 outer electrons available for bonding. In a pure crystal, each atom is bonded covalently to another 4 atoms: all of its outer electrons are bonded and therefore there are few free electrons available to conduct. This makes resistance very large. Such pure crystals are known as intrinsic semiconductors. The few electrons that are available come from imperfections in the crystal lattice and thermal ionisation due to heating. A higher temperature will thus result in more free electrons, increasing the conductivity and decreasing the resistance, as in a thermistor
Holes	When an electron leaves its position in the crystal lattice, there is a space left behind that is positively charged. This lack of an electron is called a positive hole. Even though electrons are moving, the effect is the same as if it was the hole that moved through the crystal lattice. The hole can be thought of as a positive charge carrier. In complex semiconductors it is easier to calculate what is happening in terms of 1 moving positive hole, rather than many electrons
In an intrinsic semiconductor the number of holes is equal to	the number of electrons. The generally small currents consist of drifting electrons in 1 direction and drifting holes in the other.
Doping	Semiconductor’s electrical properties are dramatically changed by the addition of very small amounts of impurities. Once doped they are known as extrinsic semiconductors. Solid state semiconductors are much smaller and use much less power than valve transistors.
Doping	Doping a semiconductor involves growing impurities such as boron or arsenic into an intrinsic semiconductor such as silicon
An in intrinsic semiconductor is	an undoped semiconductor
Fermi level	Energy of last occupied level by an electron, below this energy are completely occupied and above it are completely unoccupied
N-type semiconductors	If an impurity such as arsenic with 5 outer electrons is present in the crystal lattice then 4 of its electrons will be used in bonding with the silicon. The 5th will be free to move about and conduct. Since the ability of the crystal to conduct is increased, the resistance of the semiconductor is therefore reduced. Because of the extra electrons present, the Fermi level is closer to the conduction band than in an intrinsic semiconductor. This type of conductor is called n – type, since most conduction is by the movement of free electrons (-ve)
P-type semiconductors	The semiconductor may also be doped with an element like Indium, which has 3 outer electrons. This produces a hole in the crystal lattice, where an electron is “missing”. Because of this lack of electrons, the Fermi level is closer to the valence band than in an intrinsic semiconductor. An electron from the next atom can move into the hole created, as described previously. Conduction can thus take place by the movement of positive holes. Most conduction takes place by the movement of positively charged holes
Notes on doping	The doping material cannot be added to the semiconductor crystal. It has to be grown into the lattice when the crystal is grown so that it becomes part of the atomic lattice. Overall charge on semiconductors are still neutral The quantity of the impurity is extremely small (could be 1 atom in 1 million). If it were too large it would disturb the regular crystal lattice.
minority charge carriers	In n – type and p – type there will always be small numbers of the other type of charge carrier, known as minority charge carriers, due to thermal ionisation.
p-n junctions	When a semiconductor is grown so that 1 half is p-type and 1 half is n-type, the product is called a p-n junction and it functions as a diode. A diode is a discrete component that allows current to flow in one direction only.
At temperatures other than absolute Zero kelvin, the electrons in the n-type and the holes in the p-type material will constantly	diffuse(particles will spread from high concentration regions to low concentration regions). Those near the junction will be able to diffuse across it.
Reverse-biased	Cell connected negative end to p-type and positive end to n-type
Forward-biased	Cell connected positive end to p-type and negative end to n-type.
Reverse biased – charge carriers	When the p-side is attached to the negative side of a battery (V↓a) then the electrons at that side have more potential energy than previously. This has the effect of raising the bands on the p-side from where they were originally. We say it is reverse-biased. Almost no conduction can take place since the battery is trying to make electrons flow “up the slope” of the difference in conduction bands. The holes face a similar problem in flowing in the opposite direction. The tiny current that does flow is termed reverse leakage current and comes from the few electrons which have enough energy from the thermal ionisation to make it up the barrier.
Forward biased – charge carriers	When the p-side is attached to the positive side of the battery (V↓a) then the electrons at that side have less potential energy than under no bias. This has the effect of lowering the bands on the p-side from where they were originally. We sat it is forward biased. As the applied voltage approaches the built in voltage, more electrons will have sufficient energy to flow up the now smaller barrier and an appreciable current will be detected. Once the applied voltage reaches the in-built voltage there is no potential barrier and the p-n junction has almost no resistance, like a conductor. The holes are similarly able to flow in the opposite direction across the junction towards the negative side of the battery.
In the junction region of a forward-biased LED	electrons move from the conduction band to the valence band to emit photons.
In a forward-biased p-n junction diode, holes and electrons pass through the junction in opposite directions.	Sometimes holes and electrons will meet and recombine. When this happens energy is emitted in the form of a photon. For each recombination of electron to hole, 1 photon of radiation is emitted. Most of the time heat energy is released but in some semiconductors like gallium arsenic phosphide, the energy is emitted as light. If the junction is close to the surface of the material, this light may be able to escape. This makes an LED.
The colour of light emitted from an LED depends on	On the elements and relative quantities of the three constituent materials. The higher the recombination energy the higher the frequency of light.
The LED does not work in reverse bias since the charge carriers	do not/can not travel across the junction towards each other so cannot recombine
Photodiode	A p-n junction in a transparent coating will react to light in what is called the photovoltaic effect. Each individual photon that is incident on the junction has its energy absorbed, assuming the energy is larger than the band gap. In the p-type material this will create excess electrons in the conduction band and in the n-type material it will create excess holes in the valence band. Some of these charge carriers will then diffuse to the junction and be swept across the built-in electric field of the junction. The light has supplied energy to the circuit, enabling current to flow (it is the emf in the circuit). More intense light (more photons) will lead to more electron-hole pairs being produced and therefore a higher current. Current is proportional to light intensity.
Photodiode	The incoming light provides energy for an electron within the valance band of the p-type to be removed from a positive hole and moved up to the conduction band in the n-type material. As this electron is moved up into the conduction band it has an increase in energy. Since EMF is the energy per coulomb of charge an EMF is generated.
Photovoltaic mode	The p-n junction can supply power to a load (motor). Many photo-diodes connected together form a solar cell. This is described as photovoltaic mode. There is no bias applied to a solar cell and it acts like an LED in reverse. The increased movement of charge across a p-n junction can reduce resistance of component containing the junction.
Photoconductive mode	When connected to a power supply a photodiode will act as a LDR. This is described as photoconductive mode. The LDR is connected in reverse bias, which leads to a large depletion region. When light hits the junction, electrons and holes are split apart. This leads to free charge carriers in the depletion region. The free charge carriers reduce overall resistance of the diode, allowing current to flow. Conductivity of diode is being changed.
Addition of impurity atoms to a pure semiconductor(doping) decreases its	Resistance
Applications of p-n junctions	Photovoltaic cell /LED /Photoconductive mode(LDR)
What is photovoltaic effect?	A process in which a photovoltaic cell converts photons of light into electricity.
Depletion layer	Near the junction, electrons diffuse across to combine with holes, creating a “depletion region”.
Majority charge carriers in n-type	The electrons in the conduction band are free move towards the positive terminal of an applied p.d.
Majority charge carriers in p-type	The “positive holes” in the valance band move towards the negative terminal of an applied p.d.
Majority charge carriers across the p-n junction (forward biased)	With the applied p.d. in the direction shown electrons in the n-type material move to the left and holes in the p-type material move to the right. The depletion layer in the centre becomes thinner and thinner and if the p.d. of the supply is greater than the barrier potential(0.7 V for silicon-based semiconductors) the barrier is broken down and a current flows through the device.
How light is produced at the p-n junction of an LED	When the diode is forward biased the free electrons in the conduction band of the n-type material are given energy by the supply to overcome the energy barrier generated by the depletion layer at the junction. Once these electrons overcome the energy barrier they drop down from the conduction band to the valance band of the p-type material and combine with a positive hole in the valance band of the p-type material. As the electron drops between the bands it loses and energy and emits this as light.
Use band theory to explain how electrical conduction takes place in a pure semiconductor such as silicon.	Your explanation should include the terms: electrons, valence band and conduction band. most/majority of electrons in valance band or “fewer electrons in conduction band” band gap is small electrons are excited to conduction band charge can flow when electrons are in conduction band
What charge carriers actually move across the p-n junction?	Electrons

Now the following file is for a document from the old Higher course with a macro embedded to click on to show the applications of p-n junctions. I have saved it in compatible mode so I don’t know if the macros will work, but wordpress wont let me upload macro enabled documents (quite rightly). You’ll have to let me know if the buttons function if you download it. Enjoy! semiconductors 2017

BAND THEORY

This is the first of a selection of fantastic videos on Band Theory from the HIGH SCHOOL PHYSICS EXPLAINED Youtube channel.

High School Physics Explained

Thanks to “Paul” for allowing me to host these videos so that people in D&G can actually watch them in school! Please visit his site and subscribe…… now just how to upload them….

….still trying, but not having any success. I’ll try PLAN F. Thanks to Paul for sending me the videos which are now uploaded. The power of the internet.

Learn the following

The electrons in atoms are contained in energy levels. When the atoms come together to form solids, the electrons then become contained in energy bands separated by gaps.

In metals, the highest occupied band is not completely full and this allows the electrons to move and therefore conduct. This band is known as the conduction band.

In an insulator, the highest occupied band (called the valence band) is full. The first unfilled band above the valence band is the conduction band. For an insulator, the gap between the valence band and the conduction band is large and at room temperature there is not enough energy available to move electrons from the valence band into the conduction band where they would be able to contribute to conduction. There is no electrical conduction in an insulator.

In a semiconductor, the gap between the valence band and conduction band is smaller and at room temperature there is sufficient energy available to move some electrons from the valence band into the conduction band allowing some conduction to take place. An increase in temperature increases the conductivity of a semiconductor.

Outcome 1

Before you can pass any units you must have completed an Outcome 1. This is a practical activity that you must have been involved in. You should have collected data and written it up. See the instructions below.

There is also included below a front marking sheet that you ought to place on the front of your submitted write up.

O1 mark sheet

CANDIDATE GUIDE

Your plan must include:
• an aim — which is a clear statement of what you are trying to do in this experiment/practical investigation
• the dependent and independent variables
• the relevant variable(s) to be kept constant
• what you will be measuring/observing
• a list of equipment/materials you will use
• a labelled diagram of the experimental arrangement, if appropriate
• a description of how you will carry out your experiment/practical investigation (including safety where appropriate)
Checkpoint: Ask your assessor to check your plan before you start the practical work.
• You should carry out your experiment/practical investigation safely, including repeated measurements and averages where appropriate.
• Record your observations/measurements in an appropriate way.
Checkpoint: Ask your assessor to check your results.
• Present your findings/results in any appropriate format. You should:
— record the information/data in a clear and systematic way, with well-organised tables of raw data
— process/analyse the results. Present your findings in any appropriate format. These may be from: a table, line graph or summary. Graphs should be plotted on squared graph paper
— use appropriate SI units and standard abbreviations
• State your conclusion(s) — which should reference the aim.
• Evaluate your experimental procedures, with justification(s). Your evaluation should include two possible improvements and be supported by justification(s).

Outcome 1

1 Apply skills of scientific inquiry and draw on knowledge and understanding of the key areas of this Unit to carry out an experiment/practical investigation by:
1.1 Planning an experiment/practical investigation
1.2 Following procedures safely
1.3 Making and recording observations/measurements correctly
1.4 Presenting results in an appropriate format
1.5 Drawing valid conclusions
1.6 Evaluating experimental procedures

To pass this assessment you will have to show that you have met this Outcome and Assessment Standards.
Your assessor will let you know how the assessment will be carried out and any required conditions for doing it.

What you have to do
This assessment activity is an experiment/practical investigation.
Your assessor will provide you with the resources you need. You may be able to work in a group to do the practical work, but your assessor will need you to show that you have met the Assessment Standards.
To pass this assessment, you will have to prepare a scientific report to show that you can:
• plan an experiment/practical investigation
• make and record observations/measurements correctly
• present your results in an appropriate format
• draw valid conclusions
• evaluate experimental procedures
While you are carrying out your experiment/practical investigation, your assessor will be observing to make sure that you are following procedures safely, and that you are making measurements correctly.

Experimental Write Up

Your best work. Rulers, sharp pencils, colour etc.

Correct use of terminology and units at all times

NO WAFFLE!

Title Short and relevant with date.

Aim What are you trying to find out/prove?

To find out how “something” affects “something else”.

Method Instructions on how to complete the experiment; make it reliable and make it a fair test:

Set up the following apparatus (draw a good labelled diagram).

The “something” was set at a “value” and increased by an “amount” using the “piece of equipment”. The “something else” was noted at each value using the “other piece of equipment”. Other variables were kept constant by…….

Results Display the findings.

A neat table with headings and units.

An appropriate graph of “something” on the x-axis and “something else” on the y-axis.

Conclusion What did you find out?

As the “something” is increased / decreased, the “something else” increased / decreased / stayed the same. Also include “directly/inversely proportional” if appropriate.

Evaluation Are there any improvements that could be made to your experiment to reduce uncertainties?

Where to find your materials

If you want to find notes for each section of your course click on the individual sections from the drop down menu. Happy hunting! It is all there!

Protected: Scholar Revision

New Secret Sign of the Physicist

For years I’ve struggled with the best way to teach force on a moving particle in a field. Tom Balanowski first introduced me to the “slap” method and this year with the help of the 2016-2017 Higher Physics Group we have got it sorted!

slap-rule

Use the Left-hand Slap Rule where the four fingers of the left point in the direction of the magnetic field B and the thumb points in the direction of the moving charge or current, the direction of slapping would be the direction of force F on the conductor.

So how to deal with positive and negative charges. We decided that this method can be used for both. If the charge is negative the slap is the way the palm points. If the charges are positive then use the back of the hand, which is far more Painful

Pain = Positive

Thanks to Amy for these! Note the arrow for the force, should really be coming out of the hand or the way the slap goes; Amy drew this on her hand before I had told her about the × and • -kinaesthetic learner!

Secret sign1

secret back hand

Protected: Homework answers

Particles and Waves Resources

Powers of Ten- this was high tech when I was at school!

Since then a few things have moved on, not least with the physics as well as the graphics.

Orders of Magnitude

The class of scale or magnitude of any amount, where each class contains values of a fixed ratio (most often 10) to the class preceding it. For example, something that is 2 orders of magnitude larger is 100 times larger; something that is 3 orders of magnitude larger is 1000 times larger; and something that is 6 orders of magnitude larger is one million times larger, because 10² = 100, 10³ = 1000, and 10⁶ = one million
In its most common usage, the amount scaled is 10, and the scale is the exponent applied to this amount (therefore, to be an order of magnitude greater is to be 10 times, or 10 to the power of 1, greater).
Orders of magnitude are generally used to make very approximate comparisons and reflect very large differences. If two numbers differ by one order of magnitude, one is about ten times larger than the other. If they differ by two orders of magnitude, they differ by a factor of about 100. Two numbers of the same order of magnitude have roughly the same scale — the larger value is less than ten times the smaller value.
Source: Boundless. “Order of Magnitude Calculations.” Boundless Physics Boundless, 26 May. 2016. Retrieved 23 Jan. 2017 from https://www.boundless.com/physics/textbooks/boundless-physics-textbook/the-basics-of-physics-1/significant-figures-and-order-of-magnitude-33/order-of-magnitude-calculations-203-6080/

The-History-of-the-Atom-–-Theories-and-Models Download

A proton is 3 orders of magnitude larger than a positron or electron.

Below are the updated 2019 versions. Currently the book is divided into the Standard Model, Forces and Particles and Nuclear Radiation in Part 1 and the waves part will be in part 2, which I have yet to finalise. If you want a colour copy, then you’re welcome to print it out at your own cost.on

P&W Part 1 2019 pdf Download

P&W Part 1 2019 word Download

P&W ANSWERS Now most of the notes are complete I can start working through the answers. I have got these in a jotter, but will plod through them as quick as I can. They are very slow to type up in equation editor.

…and finally the Particles and Waves book 2 is finished.

P&W Part 2 2019 pdf Download

P&W Part 2 2019 word Download

Particles and Waves Knowledge Organiser P1

Particles and Waves

H-Particles-Knowledge-Organiser-2022 word Download

H-Particles-Knowledge-Organiser-2022 pdf Download

H P&W (Waves) Knowledge Organiser word Download

H P&W (Waves) Knowledge Organiser pdf Download

Additional Resources- take your pick

Introduction to Particle Physics

The following two documents are a wonderful summary of the Particles and Waves topic from the Revised Higher course courtesy of George Watson’s College, which is very much the current CfE Higher Course.

Particles & Waves

Here’s a lovely little revision sheet on the Standard Model thanks to Mr Ian Cameron.

Standard Model IC word version

Standard Model IC pdf version

particleadventure.org/

Below are some cracking resources from Sally Weatherly, find her here!

The-History-of-the-Atom-EXPERIMENT Download

The-History-of-the-Atom-SAMPLE-DATA Download

The-Photoelectric-Effect-EXPERIMENT Download

The-Planck-Relationship-EXPERIMENT Download

The-Planck-Relationship-SAMPLE-DATA Download

New for 2021 Powerpoints!

Revision and Orders of Magnitude

PW-N5-revision-and-Orders-Mag ppp Download

Orders of magnitude cut out base

The Standard Model

The-Standard-Model powerpoint Download

The-Standard-Model pdf Download

How to tell a MESON from a BARYON (Stewart, K (2017))

MESON- two syllables = 2 quarks (a quark and antiquark pair)

BARYON- three syllables = 3 quarks

Sorting the Fundamental Particles

Standard Model Street

Standard Model Tweet

#Higgs Boson

= fundamental particle, used by HiggsField 2 interact with other particles 2 give them m, causes particles to slow, ∴cannot reach c due to m.

found the ∴ sign 2022 is looking good

Charged Particles on Fields

Charged Particles in Fields ppp Download

Charged Particles in Fields pdf Download

Tutorials-for-Particles-in-Fields Download

Temp-answers Download

Particle Accelerators

Particle-Accelerators-ppp Download

Particle-Accelerators pdf Download

Nuclear

I don’t know who was the original source of some of this material on Physics Resources but thanks! Hope you don’t mind I updated it.

nuclear ppp Download

Nuclear-pdf Download

Tokamak-Energy-Leaflet

Inverse Square Law

inverse-square-law pdf of ppp Download

inverse-square-law ppp Download

Wave particle Duality

Interference

Spectra

Line Spectra

Refraction

I’ve had to split this as it is too big. The second part will appear after Friday

The pdf obviously doesn’t have the video clips!

H-Refraction-with-N5-revision ppp Download

H-Refraction-with-N5-revision pdf Download

Ready to go Refraction Graph excel spreadsheet Download

Other resources

quantum model of atom

quantum model of atom answers

atomic-timekeeping-poster

q uantum model of atom Mrs Physics’ model of energy level, to help you remember, not necessarily to teach you Physics!

quantum model of atom answers Mrs Physics’ model of energy level answers. Don’t look at these until you’ve tried them yourself!

These are the tweets from the higher class this 2017. Describe in under 140 characters the following words. Let us know if you can do better. Some of the tweets are a little over as there are no symbols in wordpress that I can find.

TERM	DEFINITION (140 characters or less)
#4 FUNDAMENTAL FORCES	Fundamental forces: interactions that cannot be reduced. There are 4 types. The forces keep all matter together in the universe.
#ANNIHALATE	Process in which a particle and antiparticle unite, annihilate each other, and produce 1 or more photons. Energy and momentum are conserved.
#ANTIMATTER	Matter consisting of elementary particles which are the antiparticles of those making up normal matter.
#BARYON	A subatomic particle which contains 3 quarks. Baryons are hadrons.
#BOSON	A subatomic particle, such as a photon, which has zero or integral spin. All the force carrier particles are bosons.
#COLOUR	Particle has 3 apparently identical quarks but have different properties categorised by colour to satisfy Pauli Exclusion Principle
#ELECTROMAGNETIC FORCE	1 of 4 fundamental forces. influencing electrically charged particles. Responsible for electricity, magnetism and light and holds p+ and e- together
#ELECTROMAGNETIC FORCE	Affects electrically charged particles. Responsible for electricity, magnetism, & light;holds e- and p+ in atoms; allows atoms to bond to form molecules. Causes objects to be solid
#EXCHANGE PARTICLE	Particle that carries forces for strong force – gluon, weak force – W and Z bosons, electromagnetic – photon and gravitational – graviton.
#FERMION	Matter particles e.g. proton, neutron and electron. Can be hadrons or leptons
#GLUON	A supposed massless subatomic particle believed to transmit the force binding quarks together in a hadron. They mediate the strong force.
#GRAVITATIONAL FORCE	A force that attracts any object with mass.
#HADRON	A particle made of quarks. Two families: baryons – made of 3 quarks & mesons – made of 1 quark & 1 antiquark. Protons & neutrons are baryons
#HIGGS BOSON	fundamental particle, used by Higgs Field, to interact with other particles two give them m, causes particles to slow therefore cannot reach c due to m.
#LEPTON	Elementary particles, the basic building blocks of matter. Six leptons are in present structure. Varieties are called flavours.
#MESON	Are intermediate mass particles that are made of a quark- antiquark pair. Mesons are bosons and hadrons.
#MUON	A particle similar to the electron, with an electric charge of −1 e and a spin of 1/2, but with a much greater mass. It is classified as a lepton.
#NEUTRINO	A neutral subatomic particle. Mass close to zero. Half-integral spin.Rarely reacts with normal matter. 3 types of neutrino are electron, muon and tau.
#POSITRON	Positron= antielectron =the antiparticle of the electron has an electric charge is +1 e, a spin of 1/2, same mass as an electron.
#QUARK	Quark: a fundamental particle. Quarks combine to form composite particles called hadrons. The most stable hadrons are protons and neutrons.
#SPIN	All particles have spin. Can be up or down & has a fixed value which depends on the type of particle. Particles can be right or left handed
#STANDARD MODEL	Theory concerning electromagnetic, gravitational, strong and weak nuclear interactions and classifying all known subatomic particles.
#STRONG FORCE	Binds quarks together to make subatomic particles e.g.protons and neutrons. Holds together the atomic nucleus. Causes interactions between particles that have quarks.
#WEAK FORCE	A force that plays a role in things falling apart, or decaying.

Mrs Physics was given a tweet to do too. I think she did very well, exactly 140 characters with spaces!

Prof Aidan Robson (Glasgow University)

Hope no one gets to this stage!

It is not as Mrs B said Mrs H’s Bohring Model, but it is more like a Stewart method of remembering the Bohr model!

quantum model of atom

quantum model of atom answers

Photomultipliers- what the heck are they?

https://study.com/academy/lesson/how-photomultiplier-tubes-array-detectors-work.html

Simulations

Here are three links to some cracking simulations for this topic

https://www.cabrillo.edu/~jmccullough/Applets/Applets_by_Topic/Superposition_Interference.html

http://galileoandeinstein.physics.virginia.edu/more_stuff/Applets/rutherford/rutherford2.html

http://science.sbcc.edu/physics/flash/siliconsolarcell/bohratom.swf

PhET Interactive Simulations
University of Colorado Boulder
https://phet.colorado.edu

Click to Run

https://phet.colorado.edu/en/simulation/rutherford-scattering

Anderson High school Shetland Notes

With grateful thanks to Ms Nancy Hunter from Anderson High School in Shetland. Apparently these have been voted as the best Higher notes.

pw-booklet-1-teacher-20161212

pw-booklet-2-teacher-20161212

Online simulations

There is a great simulation from Phet Colorado Physics. It is fantastic and we must support this great site.

https://phet.colorado.edu/en/simulation/photoelectric

PhET Interactive Simulations
University of Colorado Boulder
https://phet.colorado.edu

Click to Run

This is a great little introduction to Chapter 7 Interference and Diffraction.

A great poster from NPL- measurements are in their care! The poster shows how time keeping has got more and more precise.

atomic-timekeeping-poster Download

Scholar Notes

hg_cphy_Unit2

Mrs Physics

Updated January 2022

Perfect Answers (according to the SQA)

I will add and adapt these as I go through the past papers. If you’ve got additional definitions do pass them on. These would be great written on cue or flash cards. Go through past papers and record any common phrases or answers.

perfect answers.xlsx

	Term	Definition
1	acceleration	Acceleration is the rate of change of velocity
2	acceleration of X ms-2	The velocity of the body increases/changes by X m s-1 every second.
3	Air bags / crumple zones / seat belts	Time (of collision) increased, change in momentum is the same, (Average) force (acting on passenger) is decreased/reduced/smaller
4	Big Bang Description	The Universe was initially in a hot and very dense state and then rapidly expanded. The universe started from a point/singularity and rapidly expanded.
5	Big Bang Evidence	Cosmic Microwave Background Radiation, Redshift of galaxies, Olber’s Paradox (and darkness of the skies), H-He Problem (relative abundance of hydrogen/helium)
6	Closed universe	The universe will slow its expansion and eventually begin to contract.
7	Collisions- law of conservation of momentum	During any collision, in the absence of external forces momentum is conserved, total energy is conserved. In an elastic collision – Ek is also conserved In an inelastic collision- Ek is transferred into other forms.
8	Component of weight down a slope	W sin θ, or mg sin θ
9	Cosmic Microwave Background Radiation. CMB Give a reason why the existence of this radiation supports the Big Bang Theory.	is pervasive throughout space. It is the dominant source of radiation in the Universe. It is very uniform (throughout the Universe). It is isotropic (throughout the Universe). It shows the characteristics of blackbody radiation. It has a temperature of approx 3 K (2·74 K) due to cooling on expansion. It corresponds to a redshift of 1000, so the early temperature of this radiation was approx 3000 K. CMBR is thought to be the “afterglow” of the Big Bang, cooled to a faint whisper in the microwave region.
10	Dark Energy	a hypothetical form of energy whose negative pressure counteracts gravity and is assumed to be responsible for the universe expanding at an accelerating rate. Dark Energy repels.
11	Dark Matter	a hypothetical form of matter invisible to electromagnetic radiation, postulated (suggested) to account for gravitational forces observed in the universe. Dark Matter is attractive
12	Doppler Effect	The Doppler Effect is the apparent change in frequency of a wave when the source and observer are moving relative to each other.
13	Doppler explanation	There are more wavefronts per second observed due to the forward motion of the vehicle. (NB not wavefronts produced as there are not!)
14	Evidence for the big bang	The cooling of the Universe and cosmic microwave background radiation provide evidence for the Big Bang
15	Explain why a greater number of muons are detected on the surface of the Earth than would be expected if relativistic effects were not taken into account.	For an observer on Earth’s frame of reference the mean life of the muon is much greater OR The distance in the muon frame of reference is shorter
16	Explain why star is redshifted.	The star is moving away from the Earth • The apparent wavelength of the hydrogen spectra from the star has increased • The apparent frequency of the hydrogen spectra from the star is less than the actual frequency on Earth • The frequency of the light from the star has shifted towards the red end of the spectrum • Light from the star is experiencing a Doppler shift.
17	Explain why the driving force must be increased with time to maintain a constant acceleration.	The faster it goes, the greater the air resistance. or frictional forces / friction / drag then F(drive) constant, the unbalanced force would decrease or increasing F(drive) keeps the unbalanced force constant or overall/net force – must have
18	Explain, in terms of the forces, why there is a maximum angle of slope that the cart can ascend.	As angle (of slope) increases mgsinθ increases When mgsinθ ≧ engine force – friction, the vehicle cannot move up the slope
19	F-t graphs	The Area under a F-t graph is equal to impulse or change in momentum of the object.
20	Hubble Constant Ho and 1/Ho	the ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer. The reciprocal of the constant is called Hubble time and represents the length of time for which the universe has been expanding, and hence the age of the universe.
21	impulse	This quantity Ft is called the IMPULSE and it is equal to the CHANGE IN MOMENTUM of the object. Impulse = change in momentum
22	inertia	Inertia is the tendency of a body to remain at rest, or if moving, to continue its motion in a straight line
23	inertial reference frame	two objects that are moving at constant speed with reference to each other
24	Law of conservation of momentum	Total momentum before (a collision) is equal to the total momentum after (a collision) in the absence of external forces
25	Length contraction	The decrease in length (in the direction of motion) of an object moving relative to an observer. N.B. it must be clear that the observer is in a different frame of reference.
26	Lorenz transformation not noted at low speeds.	Lorentz factor is (approximately) unity/equal to one negligible change in length/time/mass observed
27	momentum	the product of mass times velocity
28	Newton- definition	One Newton is equal to the force which causes an acceleration of one metre per second squared when applied to a mass of one kilogram.
29	Open Universe	The universe will continue to expand forever.
30	Radiation of peak wavelength 1·06 mm can be detected on Earth coming from all directions in space.	Cosmic Microwave Background All three words required (Radiation) “CMBR” – Not acceptable, as this is not “naming”.
31	Redshift example	More distant galaxies are moving away at a greater velocity/ have a greater recessional velocity
32	Redshift explanation	Light from objects moving away is shifted to larger wavelength or the rate of change of wavelength/emitted wavelength as the galaxy moves away
33	Redshift, z	Redshift, z, of a galaxy is defined as the change in wavelength divided by the original wavelength, and given the symbol z. It has no units.
34	Reference Frame	The background frame against which measurements are made. There is no absolute reference frame.
35	Resultant force	A single force that has the same effect as the forces actually acting on an object
36	Satellites a curved path	Constant horizontal speed but are accelerating in the vertical direction under the influence of a gravitational field.
37	scalar and vector	A vector is a quantity which has both a magnitude and direction. A scalar is fully described by its magnitude.
38	Spectral lines	A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range. Spectral lines are often used to identify atoms and molecules from their characteristic spectral lines. These “fingerprints” can be compared to the previously collected “fingerprints” of atoms and molecules, and are thus used to identify the atomic and molecular components of stars and planets.
39	Terminal Velocity	A constant velocity of an object when the driving force acting on an object is balanced by the frictional force.
40	Time dilation	Time dilation is a difference in a time interval as measured by a stationary observer and a moving observer.
41	twin paradox	Special Relativity would suggest one twin who has been out in space or travelling at high speed relative to one remaining on Earth should come back younger, but to the travelling twin they could consider themselves stationary as the Earth moved away fast, so to the astronaut twin the twin on Earth should be younger. This paradox is resolved as during the journey in space the travelling twin would have had to return, during which time they would be in a non-inertial reference frame, so they would have experienced the speed/acceleration. Therefore been in a non inertial reference frame and hence special relativity does not apply.
42		Speed of light is the same for all observers / all (inertial) frames of reference
43		Correct – from the perspective of the stationary observer there will be time dilation Incorrect – from the perspective of the students they are in the same frame of reference as the clock Not possible to say/could be both correct and incorrect – frame of reference has not been defined
44		light is redshifted/ shifted towards red

Proving the equations of motion

Equation 1

v u at

Equation 2

v-t graph s ut 12at2

Equation 3

EOM equation 3

If you don’t like proving v²=u²+2as from v=u+at then use this neat little sheet from Mr Mackenzie.

using displacement equation to prove the last equation

Below are the 16 graphs to try to learn. Going across a row from L to R shows graphs drawn from the gradient of the previous graph. Therefore if you write the axes on for s-t, v-t and a-t you can work backwards and forwards to quickly picture the shape of the graph you require. 16graphs

Friction always acts to oppose motion. If the object is sliding down the slope then friction must act up the slope, but if the object is being pushed up the slope then friction acts down the slope. friction down slope friction up slope The component pushing into the slope (mg cosθ) is balanced by the reaction force from the slope.

Lifts

lifts

Collisions Seatbelts, crumple zones, airbags, helmets etc are all designed to reduce the force on a person, by increasing the time of contact. In all cases the change in momentum or impulse remains the same as the vehicle/ object still has to come to rest from its initial speed. lower force

F=GMm/r²=mg

finding g

Show that the frequency f of the sound heard by the passenger is given by where symbols have their usual meaning. Doppler proof

Although we talk about the Big Bang, it is important to emphasise that the universe, ie space, is expanding. There are a number of characteristics that indicate it is an expansion and not the result of an explosion.

Explosion	Expansion
Different bits fly off at different speeds	Expansion explains the large-scale symmetry we see in the distribution of galaxies
Fast parts overtake slow parts	Expanding space explains the redshifts and the Hubble law
Difficult to imagine a suitable mechanism to produce the range of velocities from 100 kms–1 to almost the speed of light	Expansion also explains redshifts and the Hubble law even if we are not at the centre of the universe

*Type of Collision*	*Momentum*	*Kinetic Energy*	*Total Energy*
Elastic	Conserved	Conserved	Conserved
Inelastic	Conserved	Reduced	Conserved
Explosions	Conserved zero at start and finish	here E_p is converted to E_k so E_k increases	Conserved

Hope these are helpful. Let me know if you want me to add anything further.