An LED is FORWARD biased. A photon is emittedwhen an electronfalls from the conduction band into the valence band.
Power Matching (word) Power Matching (pdf) Here is a task to show how to get the greatest power from your circuit. I’ve uploaded it as a pdf and word document.
Here are the answers in an excel spreadsheet, but don’t peek until you’ve completed your own graphs and table! power matching
final-question-past-paper Here are the questions from the Revised Higher Physics Papers in topic order with the marking instructions. If you can’t read this I can upload as a pdf file, just ask!
A graph of current against time for charging and discharging at different frequencies. Notice how at low frequencies (0-16s) the current can drop quite low, whereas at higher frequencies (16-26s) their is greater current overall.
Here is a nice introduction to semiconductors
Band Theory
My powerpoint for this section contains some exciting explanations that I’ve “borrow” from Chris Hooley, Paul at High School Physics Explained and helpmyphysics. The first powerpoint is 588MB so I’ve had to break it up to upload it. If you want to use it you’ll need to download each part and paste it all back together!
This is the first section of semiconductors but I’ve ad to break it up to upload it
I’ve taken out the embedded videos so some of the helpmyphysics, you might need to cut some of it. Hope it helps you.
[table id=16 /]
2016 Higher Question Paper
Some cars use LEDs in place of filament lamps. An LED is made from semiconductor material that has been doped with impurities to create a p-n junction. The diagram represents the band structure of an LED.
A voltage is applied across an LED so that it is forward biased and emits light.
Using band theory, explain how the LED emits light.
(Voltage applied causes) electrons to move towards conduction band of p-type/ away from n-type (towards the junction) (1)
Electrons move/ drop from conduction band to valence band (1)
Thanks to N. Hunter for these great notes from Anderson High.
This is the end of the course! Thanks for making the journey with me. Just revision to do now. All of those resources can be found in the REVISION section.
Worked Answers
For speed I will add some of the worked answer files here until I can produce an answer booklet, which I’ll do a.s.a.p.
You moaned and I responded. Here are just the notes for the ODU section, no questions to put you off. I will move the questions to the Learning Outcome Booklet.
Well after spending 18 months or more several years ago putting everything together students have unanimously declared they want everything separated, so your wish is my command students- here is the complete Our Dynamic Universe section notes with nothing but the essential practicals plus one!
These are part 1 of the notes in pdf format, so you all ought to be able to open them. There is a word version underneath.
I’ve removed the Time Dilation detailed version and added it as a separate document as I suspect most of you wont read them; which is a pity as it makes everything seem fine! Based on Russell Stannard’s excellent book “Relativity- a very short introduction” Oxford. (2008) ISBN 978–0–19–923622–0)
ODU worked ANSWERS_4 Currently the most up to date version of the worked answers.
ODU worked ANSWERS_4 The pdf version of the most up to date version of the worked answers.
These are powerpoints prepared for the Revised Higher in 2000. They are still relevant now, and talk through example questions. They are great for revision.
It might be old, but sometimes the old ones are the best. Link for the ppp below!
Linked to some talking questions and answer. ppp below
For those struggling with the vectors try these to give you some practice Great Resource from Mr Crookes. Set up your 2 vectors, either use a scale diagram or components and compare to the given answer. Enjoy!
If you don’t like proving v2=u2+2as from v=u+at then use this neat little sheet from Mr Mackenzie.
4.4 ODU EqoM 2012 this document has the macros enabled (actually I think you might need to contact me to get the macros, they are not allowed to be uploaded on a WordPress Website. It allows you to check your answers for the acceleration time graphs that you drew from the velocity time graph diagrams.
The green dots and red dots in the animation represent spaceships. The ships of the green fleet have no velocity relative to each other, so for the clocks onboard of the individual ships, the same amount of time elapses relative to each other, and they can set up a procedure to maintain a synchronized standard fleet time. The ships of the “red fleet” are moving with a velocity of 0.866 of the speed of light with respect to the green fleet.
The blue dots represent pulses of light. One cycle of light-pulses between two green ships takes two seconds of “green time”, one second for each leg.
As seen from the perspective of the reds, the transit time of the light pulses they exchange among each other is one second of “red time” for each leg. As seen from the perspective of the greens, the red ships’ cycle of exchanging light pulses travels a diagonal path that is two light-seconds long. (As seen from the green perspective the reds travel 1.73 ({\displaystyle {\sqrt {3}}}) light-seconds of distance for every two seconds of green time.)The animation cycles between the green perspective and the red perspective, to emphasize the symmetry.
The homework booklets are now in the HOMEWORK section.
Homework Booklet Complete pp6-8 (first question), 10-16, 18. Complete notes on Units prefixes and Sci Notation, Uncertainties, Equations of Motion. Read up on Forces.
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/
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 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.
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.
quantum 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!
