If you need the 2009-2011 Papers here they are…

# Category: AQA Unit 1 Particles/ Quantum/ Elec

**Permanent link to this article: **https://www.animatedscience.co.uk/2011/unit-1-as-exam-past-papers

May 09 2011

## Why do thick wires have lower resistance?

For a copper wire (at a given temperature) the speed of the electrons depends only on the voltage across it. Imagine a three-lane road and a single-lane road with cars all going at the same speed. More cars pass per second in the wider road even though the speed is the same. More cars (charges) per second means higher current for a given voltage and so smaller resistance.

Here’s an animation showing how thicker wires have a lower resistance.

Since current is the same around a simple series circuit the charges have to go faster where the wire is thinner. Faster charges mean more interactions with the ionic lattice per second and so higher resistance.

**Permanent link to this article: **https://www.animatedscience.co.uk/2011/why-do-thick-wires-have-lower-resistance

## 1 Matter Radiation

This is a topic which introduces the detail of the atom, the idea of stability, the photon model E = hf, antiparticles and the interactions of particles. There is quite a lot of wordy detail and basic facts to learn with a small number of calculations such as specific charge or E = hf to cover. Also make sure you know what an electron volt is and how to derive it from first principals. Energies may also be expressed in Joules or MeV so be sure on that one as well. Also you must visit https://www.particleadventure.org/ to read around the first three topics. If you don’t you will fail the exam! But a word of caution you will not need to know everything on the site. The AS Physics Exam does not cover every particle in the universe so check the specs!

#### Main Resources….

01 Matter and Rad Student Booklet

**Inside the atom**

1.1 Dream Journey Inside The Atom (cartoon on the atom)

**Stable and unstable nuclei**

1.2 More on Neutrinos (information sheet)

**Photons**

1.3 Lasers Extension (if you want to think more deeply about lasers)

**Particles and antiparticles**

1.4 Antimatter (cartoon on Antimatter)

1_4_Chronology of particle physics

**How particles interact**

1.5 Feynman Diagrams Worksheet (problems & solutions for Feynman Diagrams)

1.5 The Big Bang (Cartoon on Big Bang Theories)

1.5 Higgs Boson (some detail on what is the Higgs Boson)

## AS Chapter 1 Matter and Radiation

*AS Chapter 1 Matter and Radiation*. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%

**Permanent link to this article: **https://www.animatedscience.co.uk/2-particles-and-radiation/1-matter-radiation

## 2 Quarks and leptons

This topic is about learning what is inside a nucleus and essentially how does that make an atom behave. You really need to learn a lot of basic facts. You can also find loads of youtube movies, just search for the key terms and you will learn lots of things.

#### Main Resources

02 Quarks and Leptons Student Booklet

**2.1 The particle zoo**

Particle Physics Reference Booklet (Particle reference sheet)

**2.2 Particle Sorting**

2.2 ParticleAccelerators (Information sheet from Cern on Accelerators)

2.2 LHC (Information sheet from Cern on Accelerators)

**2.5 Conservation rules**

Strangeness (Strangeness Summary)

## AS Chapter 2 Quarks and Leptons

*AS Chapter 2 Quarks and Leptons*. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%

**Permanent link to this article: **https://www.animatedscience.co.uk/2-particles-and-radiation/2-quarks-and-leptons-as-unit-1

## 3 Quantum phenomena

This chapter covers the quantum phenomena of the photoelectric effect, excitation, fluorescence and line spectra. What is most important is to learn the ideas of photoelectric effect so you can construct a wordy answer to a 6-7 mark written question. Also make sure you know your Joules from your eV’s. Finally there are a lot of computer models to look at which help you visualise this topic make sure you spend the time looking through them

AS Physics Unit 3 Exam Questions

Title | What to do | Site | Type |

Different excited states for different elements | Investigate exciting electrons by collisions – many atoms | Molecular Workbench | Sim |

Emission Spectra Lab | Viewing spectra for different elements through grating, measuring position of lines | PhysAviary | Lab |

Energy Level Lab | Select electron energy level, view frequency of photon emitted | PhysAviary | Lab |

Energy levels in hydrogen | View shapes of orbitals of electrons in H | Molecular Workbench | Sim |

Excited electrons | Investigate exciting electrons by collisions – 2 atoms | Molecular Workbench | Sim |

Photoelectric Effect Lab | Adjust wavelength of radiation to emit electrons | PhysAviary | Lab |

Photoelectric Effect Lab | Adjust wavelength of radiation to emit electrons | I Want to Study | Lab |

Photoelectric Effect Lab | Simple simulation of effect, vary wavelength, p.d., metal | Kings Center | Lab |

**Permanent link to this article: **https://www.animatedscience.co.uk/2-particles-and-radiation/3-quantum-phenomena-as-unit-1

## 12 Electric Current

This is the basic introduction to current flow and circuits. Really this unit is just an extension of GCSE Electricity with some harder problems using the same rules. Also you will need to remember how each component works and be able to interpret a VI graph. Always remember to check your gradient. Since V=IR a graph of V – y-axis and I – x-axis shows R as gradient. The other way around which is how we tend to do exp shows 1/R it does matter.

Circuit Construction Kit (phet animation)

12 Electric Current (lesson PPT)

12 Electric Current Student Booklet (lesson notes for section)

**12.1 Current and charge**

aluminium (Electrolysis of Aluminium Animation)

fluid_electrolysis (Electrolysis of Copper Chloride E=VIt)

4_1_ Flow of Charge Worksheet (word)

Animation/Model of inside a battery (phet)

**12.2 Potential difference and power**

Electron Speeds Worksheet (extension – challenge!)

**Electricity Calculations & Sig Figures….. **I would advise all of you to look at this tutorial this week before you do the unit homework… https://www.chem.sc.edu/faculty/morgan/resources/sigfigs/index.html . An example is **V = 12V**, **Resistance = 62Ω**. If you work out the current through the resistor as V = IR changes to V/R = I = 12V/62 Ω = **0.193548A. **The original data is 2 sig figures so you should quote the answer to this as well. Hence…

**0.2A – Wrong ****0.19A – Correct ****0.193548A – Wrong**

12**.3 Resistance**

resistivity (animation) Use this to think about how atoms actually look inside a metal. Then imagine a drift of electrons through this.

4_3_Investigation (Practical Investigation & Worksheet)

4_3_Resistance Worksheet 1 (problems)

4_3_Resistance Worksheet 2(problems)

4.3 Resistance Networks Worksheet (problems)

Resistivity example data (this is a spreadsheet from practical with example graph)

Model (phet – resistivity of a wire)

Ohm’s Law Model (phet)

**12.4 Components and their characteristics**

4_4_Graphs Worksheet (graphing problems)

LED Forwards Bias Data (Excel) Data and graph from logger of diode in forwards bias with resistor inline.

oven temp sensor (How Science Works information sheet on thermistor at work)

Thermistors (extension reading)

Diode Problem (extra problem to look at) This one is often used in the AS exam when looking at diodes

**Youtube Video Tutorials “Electricity” – Steve4Physics**

**E01 Charge and Current. Part 1 of 2**

**E02 Charge and Current. Part 2 of 2**

**E03 Emf and voltage. Part 1 of 2**

**E04 Emf and voltage. Part 2 of 2**

**E05 IV (Characteristic) Curves Part 1 of 2**

**E06 IV (Characteristic) Curves Diodes Part 2 of 2 (diodes)**

**E07 Resistance. Part 1 of 2**

**E08 Resistance. Part 2 of 2**

**E09 Ohm’s Law**

**E12 Resistors in series**

**E13 Resistors in parallel**

**E14 The resistance of series and parallel resistor combinations**

**E23 Resistivity Part 1 of 2**

**E24 Resistivity Part 2 of 2**

**E25 Resistance and Temperature 1 of 3**

**E26 Resistance and Temperature 2 of 3. Semiconductors**

**E27 Resistance and Temperature 3 of 3 Superconductors**

**Permanent link to this article: **https://www.animatedscience.co.uk/4-electric-current-as-unit-1

## 13 Direct current circuits

This section is about applying some more advanced rules to circuits that build on your GCSE skills. The trick is to realise that you must be 100% logical and treat it as a mathematical exercise. If you set up the problems correctly then you cannot go wrong. Take note of these things that you must be able to do…

- Make sure you treat current and pd as having a direction.
- Learn how to apply reciprocal equations for 1/R for resistors in parallel
- Learn what the gradient and intercept mean on an Internal Resistance circuit graph
- Remember that a power source is a “real source” and will get warm so lose energy! A 3V cell does not output 3V!
- When thinking about potential dividers the trick is to realise that current is the same through each resistor. So setup two equations for V for each then I is the same for both!

13 DC Circuits (Main PPT)

13 DC Circuits Student Booklet (student booklet notes)

Donkey_Model (Think about how a model might help you?)

**13.1 Circuit rules**

5_1_kirchoffs laws (problem sheet)

**13.2 More about resistance**

5_2_Practical_investigating_resistors (Practical on Resistors)

5_2_practical_cons_energy (Practical sheet proving Kirchhoff’s laws)

resistor_cube_problem (Extension – 3D resistor cube problem – for fun!)

**13.3 Emf and internal resistance**

Internal Resistance Calculator (Hyper Physics)

5_3_EHT_Practical_Demo (teacher demo with results to graph)

5_3_Internal_Resistance Problems (probkems sheet)

5_3_IR_of_Battery variable current method (practical method 1)

5_3_IR_of_Cell adding bulbs method (practical method 2) Results 3 Cells (excel results)

5_3_IR_Practical_Higher_Ability

5_3_IOP_notes (extra reading from IOP)

**13.4 More circuit calculations**

5_4_Investigation_cell_combinations (Crucial practical which explores how PD behaves for series & parallel)

**13.5 The potential divider**

5_4_Potential_Dividers Worksheet

**Youtube Video Tutorials “Electricity” – Steve4Physics**

**E10 Kirchhoff’s First Law**

**E11 Kirchhoff’s Second Law**

**E12 Resistors in series**

**E13 Resistors in parallel**

**E14 The resistance of series and parallel resistor combinations**

**E15 Internal Resistance 1 of 4**

**E16 Internal Resistance 2 of 4**

**E17 Internal Resistance 3 of 4**

**E18 Internal Resistance 4 of 4**

**E19 Potential (Voltage) Dividers**

**E20 Potentiometers**

**E21 Power in Electrical Circuits – Part 1 of 2**

**E22 Power in Electrical Circuits – Part 2 of 2**

**E25 Resistance and Temperature 1 of 3**

**E26 Resistance and Temperature 2 of 3. Semiconductors**

**E27 Resistance and Temperature 3 of 3 Superconductors**

**E28 Circuits – Problem Solving**

**Permanent link to this article: **https://www.animatedscience.co.uk/5-direct-current-circuits-as-unit-1

## 6 Alternating currents

This section is partly about learning to use and oscilloscope and partly about working out RMS currents and converting between A.C. and D.C. You must learn how to do both.

AS Physics Unit 1_6 (main notes / PDF)

**6.1 Alternating current and power**

Rectification (extension)

6_1_AC_worldwide (wider reading)

**6.2 Using an oscilloscope**

6_2 Practical Using OSC (you need this to help you work the osc)

6_2_Oscilloscope Handbook (information for using OSC)

6.2 Oscilloscope Problems (worksheet)

6_2 Using an Osc (extension)

virtual osc (Very good virtual Oscilloscope – download, unzip and run in Internet Explorer. Use for 6.2 lesson)

**Youtube Video Tutorials “Electricity” – Steve4Physics**

**E29 The Oscilloscope**

**E30 Alternating Current (AC) Part 1 of 2**

**E31 Alternating Current (AC) Part 2 of 2**

**Permanent link to this article: **https://www.animatedscience.co.uk/6-alternating-currents-as-unit-1