Free resource · O-Level and SEC (G3)

O-Level Physics Formula Sheet (6091): Free PDF

The O-Level Physics paper does not print a formula list, so every equation has to be memorised. The main ones are W = mg, F = ma, p = F/A, ρ = m/V, Ek = ½mv², Ep = mgh, E = mcΔθ, v = fλ, Q = It, R = V/I, P = VI and the transformer equation Vp/Vs = Np/Ns. The 2027 SEC (G3) Physics syllabus K323 asks for the same equations.

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First page of the O-Level Physics Formula Sheet PDF

No formula list: memorise

Formulas the O-Level Physics paper does not give you

There is no formula list in the O-Level Physics paper, so these all have to be known by heart. Each one is in the syllabus.

Physical quantities, units and measurement

Prefixes for sub-multiplesnano, micro, milli, centi, deci: $n = 1 0^{- 9}, μ = 1 0^{- 6}, m = 1 0^{- 3}, c = 1 0^{- 2}, d = 1 0^{- 1}$

Prefixes for multipleskilo, mega, giga, tera: $k = 1 0^{3}, M = 1 0^{6}, G = 1 0^{9}, T = 1 0^{12}$

Kinematics

Average speedin m/s, km/h or cm/s. Speed has no direction. Velocity is speed in a stated direction: $average speed = \frac{distance travelled}{time taken}$

Accelerationchange in velocity divided by time taken, in m/s². u is the initial velocity and v the final velocity: $a = \frac{v - u}{t}$
Displacement from a velocity-time graphfor motion with uniform velocity or uniform acceleration: $displacement = area under the velocity-time graph$
Acceleration of free fallconstant for a body near the Earth: $g \approx 10 m/s^{2}$

Dynamics

Weightg is the gravitational field strength, the gravitational force per unit mass, in N/kg: $W = m g$
Resultant forceF is the resultant force in N, m the mass in kg and a the acceleration in m/s²: $F = ma$

Turning effects of forces

Moment of a forced is the perpendicular distance from the pivot to the line of the force. Unit N m: $moment = F \times d$

Principle of momentsabout any pivot, for a body in equilibrium: $sum of clockwise moments = sum of anticlockwise moments$

Pressure

Pressureforce per unit area, in Pa or N/m²: $p = \frac{F}{A}$
Densityin kg/m³ or g/cm³: $ρ = \frac{m}{V}$

Pressure due to a liquid columnh is the height of the column and ρ the density of the liquid: $p = h ρ g$

Energy

Kinetic energyin J, with m in kg and v in m/s: $E_{k} = \frac{1}{2} m v^{2}$
Gravitational potential energynear the Earth's surface: $E_{p} = m g h$

Work doned is the distance moved in the direction of the force: $W = F \times d$
Powerenergy transferred divided by time taken, in W: $P = \frac{E}{t}$
Efficiencymultiply by 100% to give a percentage: $efficiency = \frac{useful energy output}{total energy input}$

Thermal properties of matter

Heat capacityenergy needed per unit change in temperature, in J/°C or J/K: $C = \frac{E}{Δ θ}$
Energy to change temperaturec is the specific heat capacity and Δθ the change in temperature: $E = m c Δ θ$

Energy to change statel is the specific latent heat, in J/kg or J/g. The temperature stays the same: $E = m l$

General properties of waves

Wave speedf is the frequency in Hz and λ the wavelength in m: $v = f λ$
Period and frequencyT is the period in s: $T = \frac{1}{f}$

Light

Law of reflectionangle of incidence equals angle of reflection, both measured from the normal: $i = r$
Refractioni is the angle of incidence and r the angle of refraction. The constant is the refractive index n: $\frac{sin i}{sin r} = constant$

Refractive indexa ratio, so it has no unit: $n = \frac{speed of light in vacuum}{speed of light in the medium}$

Current of electricity

ChargeQ in C, I in A, t in s: $Q = I t$
Electromotive forcework done per unit charge by the source in driving charges around a complete circuit, in V: $E = \frac{W}{Q}$

Potential differencework done per unit charge in driving charges through a component, in V: $V = \frac{W}{Q}$
Total e.m.f. of sources in series: $E = E_{1} + E_{2} + E_{3} + \dots$
Resistancein Ω: $R = \frac{V}{I}$
Resistance of a wireproportional to the length l and inversely proportional to the cross-sectional area A: $R \propto \frac{l}{A}$

D.C. circuits

Series circuitthe same current at every point, and the p.d.s add up: $I = I_{1} = I_{2}, V = V_{1} + V_{2}$
Parallel circuitthe branch currents add up, and every branch has the same p.d.: $I = I_{1} + I_{2}, V = V_{1} = V_{2}$

Resistors in series: $R = R_{1} + R_{2} + R_{3} + \dots$
Resistors in parallel: $\frac{1}{R} = \frac{1}{R _{1}} + \frac{1}{R _{2}} + \frac{1}{R _{3}} + \dots$

Practical electricity

Electrical powerin W. With V = IR this also gives P = I²R = V²/R: $P = V I$
Electrical energyin J: $E = V I t$

Cost of electricityenergy in kW h is power in kW times time in hours: $cost = energy used in kW h \times cost per kW h$

Electromagnetic induction

Transformer turns ratioP is the primary coil and S the secondary coil: $\frac{V _{P}}{V _{S}} = \frac{N _{P}}{N _{S}}$
Ideal transformer powerfor an ideal transformer, power in equals power out: $V_{P} I_{P} = V_{S} I_{S}$

Radioactivity

Nuclide notationA is the nucleon (mass) number and Z the proton (atomic) number. Number of neutrons is A − Z: $_{Z}^{A} X$

Alpha decay: $_{Z}^{A} X \to_{Z - 2}^{A - 4} Y +_{2}^{4} α$
Beta decaybeta particles are taken to be β⁻ particles only: $_{Z}^{A} X \to_{Z + 1}^{A} Y +_{- 1}^{0} β$
Gamma emissionA and Z do not change: $_{Z}^{A} X \to_{Z}^{A} X + γ$
Half-life (working method)n is the number of half-lives that have passed, the time taken divided by t½: $amount left = initial amount \times (\frac{1}{2})^{n}$

Inside the PDF

4 A4 pages, ready to print. Tap a page to open the PDF there.

Questions students ask

Is a formula sheet given in O-Level Physics?

No. The 6091 syllabus asks you to recall and apply each equation and does not include a list of formulae for the paper. You need to know every equation on this sheet by heart. An approved calculator may be used in all papers.

What value of g should I use?

The syllabus states that the acceleration of free fall for a body near the Earth is constant and approximately 10 m/s². The same g is the gravitational field strength, so it can also be written as 10 N/kg.

Is this list the same for the 2027 SEC (G3) Physics paper?

Yes. The learning outcomes in the SEC G3 Physics syllabus K323 for 2027 ask for the same equations as the O-Level syllabus 6091, so this sheet works for both.

Do I need to memorise E = mc² or a lens formula?

No. The syllabus says recall of the energy-mass equivalence is not required. For lenses it asks for ray diagrams and the characteristics of images, not a lens formula. For the resistance of a wire you only need the proportionality R ∝ l/A.

Keep revising

Source

The exam paper itself is what counts on the day. If anything here differs from the SEAB document, the SEAB document is right. Tell us and we will fix it.

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