Source: https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-5-uncertainty

[Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [International A Level](https://senecalearning.com/en-gb/revision-notes/international-a-level.md) › [Physics](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics.md) › [Cambridge International](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international.md) › Uncertainty

# Uncertainty

Physics: Cambridge International A Level, topic 1.2.5

## Uncertainty

Uncertainty is a measure of how confident you can be in a measurement.  All measurements contain some amount of uncertainty. Let's say we measure a piece of string to be 10cm (to the nearest cm):

### Absolute uncertainty

![Absolute uncertainty](https://image-v2.cdn.app.senecalearning.com/2018-07/e12c850d-b9d5-4d02-b2a2-748988ccce22/Puppet-Control-String-Wood.jpg)

- The absolute uncertainty is the range of possible real values for the length of the string.
 - Length of string = 10cm ± 0.5cm
   - Our absolute uncertainty is ± 0.5cm.

### Fractional uncertainty

![Fractional uncertainty](https://image-v2.cdn.app.senecalearning.com/2018-09/2e097e52-9d36-4308-86bd-aff8ab652823/fraction.png)

- The fractional uncertainty is the absolute uncertainty divided by the measured value.
 - Fractional uncertainty = $$\frac{0.5cm}{10cm} = \frac{1}{20}$$

### Percentage uncertainty

![Percentage uncertainty](https://image-v2.cdn.app.senecalearning.com/2018-09/9d218a52-bcfd-41c0-a48f-49b9629cb4e7/percentage.png)

- The percentage uncertainty is the fractional uncertainty expressed as a percentage (i.e. multiplied by 100%).
 - Percentage uncertainty = $$\frac{1}{20} \times 100 = 5\%$$

## Uncertainty on Graphs

The range of possible values for a measurement can be shown as a line on an uncertainty graph. We call this line an error bar. Some points on a graph might not have error bars.

### Error bars

![Error bars](https://image-v2.cdn.app.senecalearning.com/2018-08/eba316bb-802e-4be3-9561-22a749cde293/error%20bars.png)

- Small uncertainties are shown by small error bars.
- Large uncertainties are shown by large error bars.

### Finding the uncertainty from a graph

![Finding the uncertainty from a graph](https://image-v2.cdn.app.senecalearning.com/2018-08/6f7491e6-a064-4470-a433-26c42c322df2/Current%20vs%20voltage.png)

- A systematic uncertainty can be spotted if the theory and the results do not match for when the independent variable is zero.
 - For example, when measuring the current in a circuit we would expect the current to be zero when the supply potential difference is zero.

### Finding the uncertainty from a graph 2

![Finding the uncertainty from a graph 2](https://image-v2.cdn.app.senecalearning.com/2018-08/ffe68344-9bb0-4284-b754-af6ff7d60752/Current%20vs%20voltage.png)

- If there is a systematic uncertainty, this expectation would not come true.
- We would see that the intercept of the line wasn't zero. 
- The intercept would indicate the size of the systematic error.
- Once the systematic error has been found, we can use the graph to find an estimate for the random error.

### Using error bars

![Using error bars](https://image-v2.cdn.app.senecalearning.com/2018-09/b3a2c5b7-1728-4761-8e3a-b4a7945afa8b/error-bars-gradient.png)

- Error bars can be used to find the steepest and shallowest possible lines of best fit.
 - The steepest possible line of best fit will have a gradient g1. 
 - The shallowest possible line of best fit will have a gradient g2.
- The uncertainty in the measurement should then be quoted as $$\frac{g_1 + g_2}{2} \pm \frac{g_1 - g_2}{2}$$.

## Test yourself on Uncertainty

- We measure the mass of a metal weight as 20 kg ± 2 kg.  What is the absolute uncertainty?
- We measure the mass of a plant pot as 20 kg ± 2 kg. What is the percentage uncertainty?
- We measure the mass of a table as 20 kg ± 2 kg.  What is the fractional uncertainty?
- What feature of a graph tells us the value of a systematic error?
- What is the equation for the uncertainty from a graph?

[Practise this topic for free](https://app.senecalearning.com/classroom/course/1b5bc325-d783-4d2c-99cd-5a7d913debfc/section/3dfa972b-8654-488f-958d-1d97c4ea3531/session)

- Previous topic: [1.2.4 Limitation of Physical Measurements](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-4-limitation-of-physical-measurements.md)
- Next topic: [1.2.6 Estimation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-6-estimation.md)

## Physics: Cambridge International A Level contents

### 1 Physical Quantities & Units
- 1.1 Physical Quantities & Units
  - [1.1.1 Use of SI Units](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-1-1-use-of-si-units.md)
  - [1.1.2 SI Prefixes, Standard Form & Converting Units](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-1-2-si-prefixes-standard-form-and-converting-units.md)
  - [1.1.3 End of Topic Test - Units & Prefixes](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-1-3-end-of-topic-test-units-and-prefixes.md)
  - [1.1.4 Avogadro's Constant](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-1-4-avogadros-constant.md)
  - [1.1.5 Scalars & Vectors](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-1-5-scalars-and-vectors.md)
- 1.2 Errors & Uncertainty
  - [1.2.1 Measuring Length, Time & Volume](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-1-measuring-length-time-and-volume.md)
  - [1.2.2 Measuring Temperature](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-2-measuring-temperature.md)
  - [1.2.3 Circuit Measurements](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-3-circuit-measurements.md)
  - [1.2.4 Limitation of Physical Measurements](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-4-limitation-of-physical-measurements.md)
  - [1.2.5 Uncertainty](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-5-uncertainty.md)
  - [1.2.6 Estimation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-6-estimation.md)
  - [1.2.7 Displaying Data](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-7-displaying-data.md)
  - [1.2.8 End of Topic Test - Measurements & Errors](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/1-2-8-end-of-topic-test-measurements-and-errors.md)

### 2 Kinematics
- 2.1 Equations of Motion
  - [2.1.1 Motion in a Straight Line](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/2-1-1-motion-in-a-straight-line.md)
  - [2.1.2 Graphs of Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/2-1-2-graphs-of-motion.md)
  - [2.1.3 Bouncing Ball Example](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/2-1-3-bouncing-ball-example.md)
  - [2.1.4 End of Topic Test - Motion in a Straight Line](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/2-1-4-end-of-topic-test-motion-in-a-straight-line.md)
  - [2.1.5 Acceleration Due to Gravity](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/2-1-5-acceleration-due-to-gravity.md)

### 3 Dynamics
- 3.1 Momentum & Newton's Laws of Motion
  - [3.1.1 Mass & Inertia](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/3-1-1-mass-and-inertia.md)
  - [3.1.2 Newton's Laws](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/3-1-2-newtons-laws.md)
  - [3.1.3 Momentum](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/3-1-3-momentum.md)
  - [3.1.4 End of Topic Test - Newton's Laws & Momentum](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/3-1-4-end-of-topic-test-newtons-laws-and-momentum.md)
  - [3.1.5 A-A* (AO3/4) - Newton's Third Law](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/3-1-5-a-a-ao34-newtons-third-law.md)
- 3.2 Non-Uniform Motion
  - [3.2.1 Projectile Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/3-2-1-projectile-motion.md)
- 3.3 Linear Momentum & Conservation
  - [3.3.1 Conservation of Momentum](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/3-3-1-conservation-of-momentum.md)

### 4 Force, Density & Pressure
- 4.1 Force, Density & Pressure
  - [4.1.1 Fields](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-1-fields.md)
  - [4.1.2 Force in Uniform Fields](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-2-force-in-uniform-fields.md)
  - [4.1.3 Friction](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-3-friction.md)
  - [4.1.4 Buoyancy](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-4-buoyancy.md)
  - [4.1.5 Terminal Speed](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-5-terminal-speed.md)
  - [4.1.6 End of Topic Test - Acceleration Due to Gravity](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-6-end-of-topic-test-acceleration-due-to-gravity.md)
  - [4.1.7 Centre of Mass](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-7-centre-of-mass.md)
  - [4.1.8 Forces & Equilibrium](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-8-forces-and-equilibrium.md)
  - [4.1.9 End of Topic Test - Scalars & Vectors](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-9-end-of-topic-test-scalars-and-vectors.md)
  - [4.1.10 Moments](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-10-moments.md)
  - [4.1.11 End of Topic Test - Moments & Centre of Mass](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-11-end-of-topic-test-moments-and-centre-of-mass.md)
  - [4.1.12 Density](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-12-density.md)
  - [4.1.13 Pressure](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-13-pressure.md)

### 5 Work, Energy & Power
- 5.1 Work, Energy & Power
  - [5.1.1 Work & Energy](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/5-1-1-work-and-energy.md)
  - [5.1.2 Power & Efficiency](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/5-1-2-power-and-efficiency.md)
  - [5.1.3 Conservation of Energy](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/5-1-3-conservation-of-energy.md)
  - [5.1.4 End of Topic Test - Work, Energy & Power](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/5-1-4-end-of-topic-test-work-energy-and-power.md)
- 5.2 Gravitational Fields
  - [5.2.1 Newton's Law](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/5-2-1-newtons-law.md)
  - [5.2.2 Gravitational Field Strength](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/5-2-2-gravitational-field-strength.md)
  - [5.2.3 Gravitational Potential](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/5-2-3-gravitational-potential.md)

### 6 Deformation of Solids
- 6.1 Materials
  - [6.1.1 Bulk Properties of Solids](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/6-1-1-bulk-properties-of-solids.md)
  - [6.1.2 Energy in Materials](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/6-1-2-energy-in-materials.md)
  - [6.1.3 Young Modulus](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/6-1-3-young-modulus.md)
  - [6.1.4 End of Topic Test - Materials](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/6-1-4-end-of-topic-test-materials.md)

### 7 Waves
- 7.1 Simple Harmonic Motion
  - [7.1.1 Simple Harmonic Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-1-1-simple-harmonic-motion.md)
  - [7.1.2 Simple Harmonic Systems](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-1-2-simple-harmonic-systems.md)
  - [7.1.3 Energy in Simple Harmonic Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-1-3-energy-in-simple-harmonic-motion.md)
  - [7.1.4 Resonance](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-1-4-resonance.md)
  - [7.1.5 End of Topic Test - Simple Harmonic Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-1-5-end-of-topic-test-simple-harmonic-motion.md)
  - [7.1.6 A-A* (AO3/4) - Simple Harmonic Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-1-6-a-a-ao34-simple-harmonic-motion.md)
  - [7.1.7 End of Topic Test - Gravitational Fields](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-1-7-end-of-topic-test-gravitational-fields.md)
- 7.2 Waves
  - [7.2.1 Progressive Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-1-progressive-waves.md)
  - [7.2.2 Intensity of Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-2-intensity-of-waves.md)
  - [7.2.3 Wave Speed & Phase Difference](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-3-wave-speed-and-phase-difference.md)
  - [7.2.4 Longitudinal & Transverse Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-4-longitudinal-and-transverse-waves.md)
  - [7.2.5 End of Topic Test - Progressive Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-5-end-of-topic-test-progressive-waves.md)
  - [7.2.6 Electromagnetic Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-6-electromagnetic-waves.md)
  - [7.2.7 Doppler Effect](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-7-doppler-effect.md)
  - [7.2.8 Sound Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-8-sound-waves.md)
  - [7.2.9 Measuring Sound Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-9-measuring-sound-waves.md)
  - [7.2.10 End of Topic Test - Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-10-end-of-topic-test-waves.md)
  - [7.2.11 Ultrasound Imaging](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-11-ultrasound-imaging.md)
  - [7.2.12 Ultrasound Imaging 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/7-2-12-ultrasound-imaging-2.md)

### 8 Superposition
- 8.1 Superposition
  - [8.1.1 Stationary Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-1-stationary-waves.md)
  - [8.1.2 Stationary Waves 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-2-stationary-waves-2.md)
  - [8.1.3 End of Topic Test - Stationary Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-3-end-of-topic-test-stationary-waves.md)
  - [8.1.4 A-A* (AO3/4) - Stationary Waves](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-4-a-a-ao34-stationary-waves.md)
  - [8.1.5 Interference](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-5-interference.md)
  - [8.1.6 Interference 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-6-interference-2.md)
  - [8.1.7 End of Topic Test - Interference](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-7-end-of-topic-test-interference.md)
  - [8.1.8 Diffraction](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-8-diffraction.md)
  - [8.1.9 Diffraction Gratings](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-9-diffraction-gratings.md)
  - [8.1.10 End of Topic Test - Diffraction](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/8-1-10-end-of-topic-test-diffraction.md)

### 9 Thermal Physics
- 9.1 Circular Motion
  - [9.1.1 Circular Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-1-1-circular-motion.md)
  - [9.1.2 Circular Motion 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-1-2-circular-motion-2.md)
  - [9.1.3 End of Topic Test - Circular Motion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-1-3-end-of-topic-test-circular-motion.md)
- 9.2 Thermal Physics
  - [9.2.1 Temperature](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-1-temperature.md)
  - [9.2.2 Measuring Temperature](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-2-measuring-temperature.md)
  - [9.2.3 Ideal Gas Law](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-3-ideal-gas-law.md)
  - [9.2.4 Ideal Gases](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-4-ideal-gases.md)
  - [9.2.5 Boyle's Law & Charles' Law](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-5-boyles-law-and-charles-law.md)
  - [9.2.6 Molecular Kinetic Theory Model](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-6-molecular-kinetic-theory-model.md)
  - [9.2.7 Molecular Kinetic Theory Model 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-7-molecular-kinetic-theory-model-2.md)
  - [9.2.8 Thermal Energy Transfer](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-8-thermal-energy-transfer.md)
  - [9.2.9 Thermal Energy Transfer Experiments](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-9-thermal-energy-transfer-experiments.md)
  - [9.2.10 End of Topic Test - Thermal Energy & Ideal Gases](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-10-end-of-topic-test-thermal-energy-and-ideal-gases.md)
  - [9.2.11 First Law of Thermodynamics](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/9-2-11-first-law-of-thermodynamics.md)

### 10 Communication
- 10.1 Communication Channels
  - [10.1.1 Communication Channels](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/10-1-1-communication-channels.md)
  - [10.1.2 Modulation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/10-1-2-modulation.md)
  - [10.1.3 Attenuation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/10-1-3-attenuation.md)
- 10.2 Digital Communication
  - [10.2.1 Digital & Analogue Signals](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/10-2-1-digital-and-analogue-signals.md)
  - [10.2.2 Representing Sound](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/10-2-2-representing-sound.md)

### 11 Electric Fields
- 11.1 Electric Fields
  - [11.1.1 Coulomb's Law](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-1-1-coulombs-law.md)
  - [11.1.2 Electric Field Strength](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-1-2-electric-field-strength.md)
  - [11.1.3 Electric Field Strength 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-1-3-electric-field-strength-2.md)
  - [11.1.4 Electric Potential](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-1-4-electric-potential.md)
  - [11.1.5 End of Topic Test - Electric Fields](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-1-5-end-of-topic-test-electric-fields.md)
  - [11.1.6 A-A* (AO3/4) - Electric and Gravitational Field](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-1-6-a-a-ao34-electric-and-gravitational-field.md)
- 11.2 Capacitance
  - [11.2.1 Capacitance](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-2-1-capacitance.md)
  - [11.2.2 Parallel Plate Capacitor](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-2-2-parallel-plate-capacitor.md)
  - [11.2.3 Energy Stored by a Capacitor](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-2-3-energy-stored-by-a-capacitor.md)
  - [11.2.4 Capacitor Discharge](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-2-4-capacitor-discharge.md)
  - [11.2.5 Capacitor Charge](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/11-2-5-capacitor-charge.md)

### 12 Current Electricity
- 12.1 Current Electricity
  - [12.1.1 Basics of Electricity](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-1-basics-of-electricity.md)
  - [12.1.2 Mean Drift Velocity](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-2-mean-drift-velocity.md)
  - [12.1.3 Current-Voltage Characteristics](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-3-current-voltage-characteristics.md)
  - [12.1.4 End of Topic Test - Basics of Electricity](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-4-end-of-topic-test-basics-of-electricity.md)
  - [12.1.5 Resistivity](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-5-resistivity.md)
  - [12.1.6 End of Topic Test - Resistivity & Superconductors](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-6-end-of-topic-test-resistivity-and-superconductors.md)
  - [12.1.7 Power and Conservation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-7-power-and-conservation.md)
  - [12.1.8 Microphones](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-8-microphones.md)
  - [12.1.9 Components](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-9-components.md)
  - [12.1.10 Relays](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-10-relays.md)
  - [12.1.11 Strain Gauges](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-1-11-strain-gauges.md)
- 12.2 DC Circuits
  - [12.2.1 Circuits](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-2-1-circuits.md)
  - [12.2.2 Potential Divider](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-2-2-potential-divider.md)
  - [12.2.3 Emf & Internal Resistance](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-2-3-emf-and-internal-resistance.md)
  - [12.2.4 End of Topic Test - Power & Potential](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/12-2-4-end-of-topic-test-power-and-potential.md)

### 13 Magnetic Fields
- 13.1 Magnetic Fields
  - [13.1.1 Magnetic Flux Density](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-1-magnetic-flux-density.md)
  - [13.1.2 End of Topic Test - Capacitance & Flux Density](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-2-end-of-topic-test-capacitance-and-flux-density.md)
  - [13.1.3 Moving Charges in a Magnetic Field](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-3-moving-charges-in-a-magnetic-field.md)
  - [13.1.4 Magnetic Flux & Flux Linkage](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-4-magnetic-flux-and-flux-linkage.md)
  - [13.1.5 Electromagnetic Induction](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-5-electromagnetic-induction.md)
  - [13.1.6 Electromagnetic Induction 2](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-6-electromagnetic-induction-2.md)
  - [13.1.7 Magnetic Flux Density](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-7-magnetic-flux-density.md)
  - [13.1.8 Magnetic Resonance Scanning](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-1-8-magnetic-resonance-scanning.md)
- 13.2 Alternating Currents
  - [13.2.1 Alternating Currents](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-2-1-alternating-currents.md)
  - [13.2.2 Operation of a Transformer](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-2-2-operation-of-a-transformer.md)
  - [13.2.3 End of Topic Test - Electromagnetic Induction & AC](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-2-3-end-of-topic-test-electromagnetic-induction-and-ac.md)
  - [13.2.4 Rectification](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/13-2-4-rectification.md)

### 14 Modern Physics
- 14.1 Quantum Physics
  - [14.1.1 The Photoelectric Effect](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-1-the-photoelectric-effect.md)
  - [14.1.2 The Photoelectric Effect Explanation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-2-the-photoelectric-effect-explanation.md)
  - [14.1.3 End of Topic Test - The Photoelectric Effect](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-3-end-of-topic-test-the-photoelectric-effect.md)
  - [14.1.4 Collisions of Electrons with Atoms](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-4-collisions-of-electrons-with-atoms.md)
  - [14.1.5 Energy Levels & Photon Emission](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-5-energy-levels-and-photon-emission.md)
  - [14.1.6 Wave-Particle Duality](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-6-wave-particle-duality.md)
  - [14.1.7 End of Topic Test - Absorption & Emission](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-7-end-of-topic-test-absorption-and-emission.md)
  - [14.1.8 Band Theory](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-8-band-theory.md)
  - [14.1.9 Diagnostic X-Rays](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-9-diagnostic-x-rays.md)
  - [14.1.10 X-Ray Image Processing](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-10-x-ray-image-processing.md)
  - [14.1.11 Absorption of X-Rays](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-11-absorption-of-x-rays.md)
  - [14.1.12 CT Scanners](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-1-12-ct-scanners.md)
- 14.2 Nuclear Physics
  - [14.2.1 Rutherford Scattering](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-1-rutherford-scattering.md)
  - [14.2.2 Atomic Model](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-2-atomic-model.md)
  - [14.2.3 Isotopes](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-3-isotopes.md)
  - [14.2.4 Stable & Unstable Nuclei](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-4-stable-and-unstable-nuclei.md)
  - [14.2.5 A-A* (AO3/4) - Stable & Unstable Nuclei](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-5-a-a-ao34-stable-and-unstable-nuclei.md)
  - [14.2.6 Alpha & Beta Radiation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-6-alpha-and-beta-radiation.md)
  - [14.2.7 Gamma Radiation](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-7-gamma-radiation.md)
  - [14.2.8 Particles, Antiparticles & Photons](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-8-particles-antiparticles-and-photons.md)
  - [14.2.9 Quarks & Antiquarks](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-9-quarks-and-antiquarks.md)
  - [14.2.10 Particle Interactions](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-10-particle-interactions.md)
  - [14.2.11 Radioactive Decay](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-11-radioactive-decay.md)
  - [14.2.12 Half Life](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-12-half-life.md)
  - [14.2.13 End of Topic Test - Radioactivity](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-13-end-of-topic-test-radioactivity.md)
  - [14.2.14 Nuclear Instability](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-14-nuclear-instability.md)
  - [14.2.15 Mass & Energy](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-15-mass-and-energy.md)
  - [14.2.16 Binding Energy](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-16-binding-energy.md)
  - [14.2.17 A-A* (AO3/4) - Nuclear Fusion](https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/14-2-17-a-a-ao34-nuclear-fusion.md)