Source: https://senecalearning.com/en-gb/revision-notes/international-a-level/physics/cambridge-international/4-1-10-moments

[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) › Moments

# Moments

Physics: Cambridge International A Level, topic 4.1.10

## Moments

The moment of a force is the turning effect it creates.

### Equation

![Equation](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.5.3%20-%20Conditions%20for%20equilibrium%20no%20resultant%20force,%20no%20net%20moment-min.png)

- The moment of a force is described by the equation:
 - Moment (Nm) = force (N) × perpendicular distance from the
point to the line of action of the force (m)
 - m = F × d

### Units

![Units](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.5.3a.1%20-%20experiment%20measuring%20moments-min.png)

- The units of moments are Newton metres (Nm).

### Example

![Example](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.5.2.2%20-%20Balanced%20moments%20example%20-min.png)

- Doors open more easily if we press (exert force) far away from the hinge, rather than next to the hinge. 
- Pushing further away from the hinge (fixed point) with the same force means the moment will be larger and the door will open more easily.

## Couples

A couple is a pair of equal and opposite coplanar forces. This means they lie in the same plane (coplanar), point in the opposite direction and have the same magnitude.

### No resultant force

![No resultant force](https://image-v2.cdn.app.senecalearning.com/2018-08/32ea787d-cc63-4503-8539-51d5144e1ac4/A%20couple.png)

- A couple has a turning effect but no resultant force.
 - Remember, the two forces in a couple are equal and opposite.

### Moment of a couple

![Moment of a couple](https://image-v2.cdn.app.senecalearning.com/2018-08/b57d1e43-21d8-40b9-9e1d-ef8a59240511/Moments%20from%20couples.png)

- Couples produce a turning effect and therefore a moment.
- The moment of a couple is defined by the equation:
 - moment of a couple = force × perpendicular distance
between the lines of action of the forces.
 - m = F × d
- Remember the 'force' in this equation refers to one of the forces in the couple - don't add them together!

## Principle of Moments

The principle of moments states that in order for an object to be in equilibrium, the sum of the clockwise moments must equal the sum of the anticlockwise moments.

### Example

![Example](https://image-v2.cdn.app.senecalearning.com/2020-02/ed294c5b-2acc-4c10-8474-d5c108437673/moments-example-min.png)

- Consider the moments on the bar in the diagram.
 - sum of anticlockwise moments = (5 × 2) + (10 × 4) = 50 Nm
 - sum of clockwise moments = F × 2 = 2F Nm

### Example cont.

![Example cont.](https://image-v2.cdn.app.senecalearning.com/2020-02/ed294c5b-2acc-4c10-8474-d5c108437673/moments-example-min.png)

- For this object to be in equilibrium (not turning):
 - 2F = 50 Nm
 - F = 50 Nm ÷ 2 m
 - F = 25 N

## Test yourself on Moments

- Why is it easier to open a door further from the hinge?
- Which of these statements are true about moments?
- What is the equation for a moment?
- What is the resultant force of a couple?
- Which of these statements are true about couples?

[Practise this topic for free](https://app.senecalearning.com/classroom/course/1b5bc325-d783-4d2c-99cd-5a7d913debfc/section/330633ab-2361-4175-a15a-5a19cab6b699/session)

- Previous topic: [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)
- Next topic: [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)

## 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)