In short: Class 11 Physics has 15 chapters and over 150 formulas spanning mechanics, thermodynamics, oscillations, and waves. This chapter-wise formula sheet covers every important equation with SI units, organised for quick revision. Bookmark this page and use it the night before exams, during chapter tests, or any time you need a fast lookup.
Why You Need a Chapter-Wise Formula Sheet
Class 11 Physics is the foundation for Class 12 boards, JEE, and NEET. Every chapter introduces new quantities, relationships, and equations. The problem most students face is not understanding the formulas - it is remembering which formula belongs where, and what units to use.
A well-organised formula sheet solves this. Instead of flipping through 400 pages of NCERT, you get every equation in one place, sorted by chapter, with units clearly listed.
This list follows the CBSE 2026-27 syllabus. If your school follows a different chapter order, use the chapter names to locate what you need.
Chapter 1 - Units and Measurements
| Formula | Expression | Unit |
|---|---|---|
| Absolute error | Delta(a) = a(measured) - a(mean) | Same as quantity |
| Mean absolute error | Delta(a_mean) = Sum of | Delta(a_i) |
| Relative error | Delta(a) / a(mean) | Dimensionless |
| Percentage error | (Delta(a) / a(mean)) x 100 | % |
Dimensional analysis tip: Use [M^a L^b T^c] format to check if your answer has the right dimensions. If the dimensions do not match, the formula is wrong - no matter how confident you feel.
Chapter 2 - Motion in a Straight Line
| Formula | Expression | Unit |
|---|---|---|
| Average velocity | v(avg) = Displacement / Time = (x2 - x1) / (t2 - t1) | m/s |
| Average speed | Total distance / Total time | m/s |
| Instantaneous velocity | v = dx/dt | m/s |
| Average acceleration | a = (v - u) / t | m/s^2 |
| First equation of motion | v = u + at | m/s |
| Second equation of motion | s = ut + (1/2)at^2 | m |
| Third equation of motion | v^2 = u^2 + 2as | m^2/s^2 |
| Distance in nth second | s(n) = u + a(2n - 1)/2 | m |
Chapter 3 - Motion in a Plane
| Formula | Expression | Unit |
|---|---|---|
| Resultant of two vectors | R = sqrt(A^2 + B^2 + 2AB cos(theta)) | Same as vectors |
| Direction of resultant | tan(alpha) = B sin(theta) / (A + B cos(theta)) | Radians or degrees |
| Projectile - time of flight | T = 2u sin(theta) / g | s |
| Projectile - max height | H = u^2 sin^2(theta) / (2g) | m |
| Projectile - range | R = u^2 sin(2 theta) / g | m |
| Centripetal acceleration | a = v^2 / r | m/s^2 |
| Angular velocity | omega = 2 pi / T = 2 pi f | rad/s |
Chapter 4 - Laws of Motion
| Formula | Expression | Unit |
|---|---|---|
| Newton's second law | F = ma | N (kg m/s^2) |
| Impulse | J = F x Delta(t) = Delta(p) | N s or kg m/s |
| Friction force | f = mu x N | N |
| Static friction (max) | f(s,max) = mu(s) x N | N |
| Kinetic friction | f(k) = mu(k) x N | N |
| Centripetal force | F = mv^2 / r | N |
| Banking angle (no friction) | tan(theta) = v^2 / (rg) | Dimensionless |
Chapter 5 - Work, Energy and Power
| Formula | Expression | Unit |
|---|---|---|
| Work done | W = F d cos(theta) | J (Joule) |
| Kinetic energy | KE = (1/2)mv^2 | J |
| Potential energy (gravity) | PE = mgh | J |
| Work-energy theorem | W(net) = Delta(KE) = (1/2)mv^2 - (1/2)mu^2 | J |
| Power | P = W/t = F v cos(theta) | W (Watt) |
| Spring PE | PE = (1/2)kx^2 | J |
| Coefficient of restitution | e = (v2 - v1) / (u1 - u2) | Dimensionless |
Chapter 6 - System of Particles and Rotational Motion
| Formula | Expression | Unit |
|---|---|---|
| Centre of mass (2 particles) | x(cm) = (m1 x1 + m2 x2) / (m1 + m2) | m |
| Torque | tau = r F sin(theta) | N m |
| Angular momentum | L = I omega = r x p | kg m^2/s |
| Moment of inertia (point mass) | I = mr^2 | kg m^2 |
| Rotational KE | KE = (1/2) I omega^2 | J |
| Parallel axis theorem | I = I(cm) + Md^2 | kg m^2 |
| Perpendicular axis theorem | I(z) = I(x) + I(y) | kg m^2 |
| Rolling without slipping | v = R omega | m/s |
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Chapter 7 - Gravitation
| Formula | Expression | Unit |
|---|---|---|
| Newton's law of gravitation | F = G m1 m2 / r^2 | N |
| Acceleration due to gravity | g = GM / R^2 | m/s^2 |
| g at height h | g(h) = g (1 - 2h/R) for h << R | m/s^2 |
| g at depth d | g(d) = g (1 - d/R) | m/s^2 |
| Gravitational PE | U = -GMm / r | J |
| Escape velocity | v(e) = sqrt(2gR) = sqrt(2GM/R) | m/s |
| Orbital velocity | v(o) = sqrt(gR) = sqrt(GM/r) | m/s |
| Kepler's third law | T^2 = (4 pi^2 / GM) r^3 | s^2 |
Chapter 8 - Mechanical Properties of Solids
| Formula | Expression | Unit |
|---|---|---|
| Stress | Stress = F / A | Pa (N/m^2) |
| Strain | Strain = Delta(L) / L | Dimensionless |
| Young's modulus | Y = Stress / Strain = (F/A) / (Delta L / L) | Pa |
| Shear modulus | G = Shear stress / Shear strain | Pa |
| Bulk modulus | B = -V (Delta P / Delta V) | Pa |
| Elastic PE per unit volume | u = (1/2) x Stress x Strain | J/m^3 |
Chapter 9 - Mechanical Properties of Fluids
| Formula | Expression | Unit |
|---|---|---|
| Pressure | P = F / A | Pa |
| Hydrostatic pressure | P = P(0) + rho g h | Pa |
| Pascal's law | F1/A1 = F2/A2 | - |
| Buoyant force | F(b) = rho(fluid) V(submerged) g | N |
| Continuity equation | A1 v1 = A2 v2 | m^3/s |
| Bernoulli's equation | P + (1/2) rho v^2 + rho g h = constant | Pa |
| Viscous force (Stokes) | F = 6 pi eta r v | N |
| Terminal velocity | v(t) = 2r^2 (rho - sigma) g / (9 eta) | m/s |
| Surface tension | T = F / L | N/m |
| Capillary rise | h = 2T cos(theta) / (rho g r) | m |
Chapter 10 - Thermal Properties of Matter
| Formula | Expression | Unit |
|---|---|---|
| Linear expansion | Delta L = L alpha Delta T | m |
| Area expansion | Delta A = A (2 alpha) Delta T | m^2 |
| Volume expansion | Delta V = V (3 alpha) Delta T = V gamma Delta T | m^3 |
| Heat absorbed | Q = m c Delta T | J |
| Latent heat | Q = m L | J |
| Conduction | Q/t = K A (T1 - T2) / d | W |
| Stefan-Boltzmann law | E = sigma T^4 | W/m^2 |
| Wien's displacement law | lambda(max) T = b (b = 2.9 x 10^-3 m K) | m K |
Chapter 11 - Thermodynamics
| Formula | Expression | Unit |
|---|---|---|
| First law | Delta U = Q - W | J |
| Work done by gas | W = P Delta V (constant pressure) | J |
| Isothermal work | W = nRT ln(V2/V1) | J |
| Adiabatic relation | PV^gamma = constant | - |
| Adiabatic work | W = (P1V1 - P2V2) / (gamma - 1) | J |
| Efficiency of Carnot engine | eta = 1 - T2/T1 | Dimensionless |
| Mayer's relation | Cp - Cv = R | J/(mol K) |
| gamma | gamma = Cp / Cv | Dimensionless |
Chapter 12 - Kinetic Theory of Gases
| Formula | Expression | Unit |
|---|---|---|
| Ideal gas law | PV = nRT | Pa m^3 |
| Kinetic energy per molecule | KE = (3/2) kT | J |
| RMS speed | v(rms) = sqrt(3RT/M) = sqrt(3kT/m) | m/s |
| Average speed | v(avg) = sqrt(8RT/(pi M)) | m/s |
| Most probable speed | v(mp) = sqrt(2RT/M) | m/s |
| Pressure from KE | P = (1/3) rho v(rms)^2 | Pa |
| Mean free path | lambda = 1 / (sqrt(2) pi d^2 n) | m |
| Degrees of freedom energy | U = (f/2) nRT | J |
Chapter 13 - Oscillations
| Formula | Expression | Unit |
|---|---|---|
| SHM displacement | x = A sin(omega t + phi) | m |
| Angular frequency | omega = 2 pi / T = 2 pi f | rad/s |
| Time period (spring) | T = 2 pi sqrt(m/k) | s |
| Time period (simple pendulum) | T = 2 pi sqrt(L/g) | s |
| Velocity in SHM | v = omega sqrt(A^2 - x^2) | m/s |
| Max velocity | v(max) = A omega | m/s |
| Acceleration in SHM | a = -omega^2 x | m/s^2 |
| Total energy in SHM | E = (1/2) k A^2 = (1/2) m omega^2 A^2 | J |
Chapter 14 - Waves
| Formula | Expression | Unit |
|---|---|---|
| Wave speed | v = f lambda | m/s |
| Speed of transverse wave (string) | v = sqrt(T/mu) | m/s |
| Speed of sound in gas | v = sqrt(gamma P / rho) | m/s |
| Progressive wave equation | y = A sin(kx - omega t) | m |
| Wave number | k = 2 pi / lambda | rad/m |
| Intensity | I = (1/2) rho omega^2 A^2 v | W/m^2 |
| Beat frequency | f(beat) = | f1 - f2 |
| Doppler effect | f' = f (v + v(observer)) / (v - v(source)) | Hz |
| Resonance (open pipe) | f(n) = nv / (2L) | Hz |
| Resonance (closed pipe) | f(n) = (2n-1) v / (4L), n = 1,2,3... | Hz |
How to Memorise 150+ Physics Formulas
Staring at a formula sheet and hoping it sticks does not work. Here is what does.
1. Group by physical quantity. All energy formulas (KE, PE, rotational KE, SHM energy) share a similar structure. Notice that (1/2) appears in most of them. Once you see the pattern, you remember 10 formulas instead of memorising 10 separate equations.
2. Derive, do not memorise. Formulas like v = u + at, s = ut + (1/2)at^2, and v^2 = u^2 + 2as all come from one starting point: a = dv/dt. If you can derive them, you will never forget them.
3. Practise with units. Every time you write a formula, write the unit next to it. This creates a second memory hook. If someone asks you for the unit of torque, you instantly recall tau = r F sin(theta) and get N m.
4. Use flashcards with Padhaao. Write the formula name on one side and the equation on the other. Test yourself in random order. Padhaao's spaced repetition approach means you revise formulas right before you would forget them.
5. Solve numericals daily. You remember what you use. Solving 5 problems a day using different formulas cements them far better than reading the formula sheet 50 times.
Common Mistakes Students Make
- Confusing velocity and speed. Velocity is a vector (displacement/time), speed is a scalar (distance/time). Using the wrong one changes your answer in projectile and circular motion problems.
- Forgetting the negative sign in gravitational PE. U = -GMm/r, not +GMm/r. The negative sign means the system is bound.
- Mixing up Cp and Cv. Cp is at constant pressure, Cv at constant volume. Cp is always greater. Mayer's relation connects them: Cp - Cv = R.
- Using degrees instead of radians. Angular velocity, SHM equations, and wave equations all use radians. If your calculator is in degree mode, every answer will be wrong.
- Applying v = u + at to non-uniform acceleration. The three equations of motion only work when acceleration is constant. For variable acceleration, use calculus.
Exam-Day Quick Revision Strategy
The morning of your exam, do not try to re-read everything. Follow this 45-minute plan:
Minutes 1-15: Scan the formula tables in this post chapter by chapter. Read each formula once, cover it, and try to recall it. Mark any formula you cannot recall with a star.
Minutes 16-30: Go back to only the starred formulas. Write each one out by hand on a blank sheet. Writing activates motor memory, which is stronger than visual memory.
Minutes 31-40: Look at 2-3 solved numericals from chapters you find difficult (usually Rotational Motion, Thermodynamics, and Waves). Focus on how the formula is applied, not on re-solving.
Minutes 41-45: Close everything. Take 10 deep breaths. You know this material. Trust your preparation.
FAQ
How many formulas are there in Class 11 Physics?
There are roughly 150-170 formulas across 15 chapters. However, many are variations of the same core equation. If you understand the 80-90 fundamental formulas, you can derive the rest.
Which chapter has the most formulas?
Mechanical Properties of Fluids and Waves tend to have the most formulas because they cover multiple phenomena. Rotational Motion also has a long list because every linear motion formula has a rotational counterpart.
Should I memorise derivations or just formulas?
Both. Formulas alone help you solve direct numerical problems, but CBSE and competitive exams also ask 3-5 mark derivation questions. Focus on key derivations like escape velocity, Bernoulli's equation, and Carnot efficiency.
Are Class 11 Physics formulas enough for JEE and NEET?
Class 11 NCERT formulas cover the syllabus, but JEE and NEET problems require deeper application. You need to practise using these formulas in unfamiliar contexts - that is where an AI tutor like Padhaao helps by generating unlimited practice problems.
How do I remember the difference between similar formulas?
Use dimensional analysis. If two formulas look similar, check their units. For example, torque (N m) and work (J = N m) have the same units but different physical meanings. Torque is a vector, work is a scalar. Context tells you which to use.
Can I use this formula sheet during revision?
Yes. This sheet is designed for quick revision before exams. Print it or keep it bookmarked on your phone. But do not use it as a substitute for understanding - use it to verify what you already know.
Start Practising These Formulas on Padhaao
Reading formulas is step one. Applying them in problems is where real learning happens. Padhaao gives you chapter-wise practice with instant feedback - if you use the wrong formula or make a unit error, the AI tutor catches it and explains why.
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