The OCR A level Physics data, formulae and relationships booklet
In every OCR Physics A exam, AS (H156) or A level (H556), you get the Data, Formulae and Relationships Booklet. It is organised by the specification's modules, so knowing its layout lets you find any equation in seconds. Here is what it contains and what it leaves out.
On this page
How the booklet is organised
- Physical constants: g, the elementary charge, the speed of light, the Planck, Avogadro, molar gas, Boltzmann and gravitational constants, the permittivity of free space, the rest masses of the electron, proton, neutron and alpha particle, and the Stefan constant.
- Quarks: the charges of the up, down and strange quarks.
- Conversion factors: the unified atomic mass unit, the electronvolt, the day, the year, the light year and the parsec.
- Mathematical equations: arc length, circle and sphere formulas, the area of a trapezium, the volume of a cylinder and sphere, Pythagoras, the sine and cosine rules, small angle approximations and the laws of logarithms.
Formulae and relationships, module by module
- Module 2, Foundations of physics: resolving vectors, Fx = F cos θ and Fy = F sin θ.
- Module 3, Forces and motion: the equations of motion, F = Δp/Δt and p = mv, moments and torque, density, pressure (including p = hρg), work, efficiency, power (P = W/t and P = Fv), and springs and materials (Hooke's law, elastic energy, stress, strain and the Young modulus).
- Module 4, Electrons, waves and photons: charge and current (I = Anev), work done, resistivity, resistors in series and parallel, power, internal resistance, potential dividers, the wave equation, intensity, double-slit spacing, refraction and critical angle, and the photon equations, including the photoelectric equation and the de Broglie wavelength.
- Module 5, Newtonian world and astrophysics: specific heat capacity and latent heat, the ideal gas equations and kinetic theory, circular motion, oscillations, gravitational fields and orbits, energy levels and gratings, Wien's law, the Stefan-Boltzmann law, and cosmology (Doppler shift, parallax, Hubble's law and the age of the Universe).
- Module 6, Particles and medical physics: capacitance and capacitor energy, the time constant and exponential charge and discharge, electric fields and potential, magnetic forces, electromagnetism and transformers, the radius of the nucleus, and further nuclear and medical physics relationships.
What you still need to know
- Definitions, such as the definition of the volt or of simple harmonic motion.
- When each equation applies, for example that the equations of motion need constant acceleration.
- Units, including derived units in base SI units.
- Practical skills, uncertainties and graph techniques, which are tested in every paper.
Module 6: capacitor discharge
A 220 μF capacitor discharges through a 10 kΩ resistor from 12 V. Find the voltage after 3.0 s.
- Time constant τ = CR = 220 × 10−6 × 10 000 = 2.2 s.
- V = V0e−t/CR = 12e−3.0/2.2 = 12 × 0.256 = 3.1 V.
Module 5: an orbit
Find the orbital period of a satellite at radius 7.0 × 106 m around the Earth (M = 6.0 × 1024 kg).
- The booklet gives T² = (4π²/GM)r³.
- T² = 39.48 × (3.43 × 1020) / (6.67 × 10−11 × 6.0 × 1024) = 3.38 × 107, so T ≈ 5.8 × 103 s (about 97 minutes).
Module 4: the photoelectric effect
Light of frequency 1.0 × 1015 Hz falls on a metal with work function 2.3 eV. Find the maximum kinetic energy of the electrons in eV.
- hf = 6.63 × 10−34 × 1.0 × 1015 = 6.63 × 10−19 J = 4.14 eV (using 1 eV = 1.60 × 10−19 J from the booklet).
- KEmax = 4.14 − 2.3 = 1.8 eV.
How to train with it
- Use the booklet in every practice paper, so you know which module each equation is in.
- Learn the definitions and conditions the booklet does not give.
- Practise unit conversions with the conversion factors: eV to J, days and years to seconds.
- AS students (H156) only need Modules 1 to 4, but the booklet is shared, so ignore the later sections.
Which modules each A level paper tests
- Paper 1, Modelling physics: Modules 1, 2, 3 and 5, so the Module 3 and Module 5 pages of the booklet are the ones you use most.
- Paper 2, Exploring physics: Modules 1, 2, 4 and 6.
- Paper 3, Unified physics: content from every module, so be ready to use any page.
Because the booklet follows the module order of the specification, matching each question to its module is the fastest way to find the right equation.
A good habit while marking past papers is to write the booklet module next to each question. After a few papers you will find any relationship without searching.
Common mistakes
- Forgetting to convert eV to joules before using E = hf.
- Using the small angle approximations in degrees.
- Mixing up the capacitor charging and discharging equations.
- Expecting definitions to be in the booklet.
Practice questions
Try each one before opening the answer.
Q1. Which module contains the ideal gas equations?
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Q2. Find the energy stored in a 470 μF capacitor at 9.0 V.
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Q3. What is 1 eV in joules?
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Frequently asked questions
Is the OCR Physics booklet the same for AS and A level?
Yes, one booklet covers H156 and H556. AS students use the sections for Modules 1 to 4.
Is it the same as OCR Physics B?
No. Physics B (Advancing Physics) has its own data sheet.
Can I take my own copy into the exam?
No. A clean copy is provided with the question paper.
Key takeaways
- One booklet for OCR Physics A, AS and A level.
- Constants, quarks, conversions and maths first.
- Then formulae by module, 2 to 6.
- Definitions, conditions and units are not given.
- Train with it in every practice paper.