Class 12 Physics Formula Sheet PDF: Important Formulas for 2026–27

Preparing for your Class 12 Physics board exam? A well-organized formula sheet can help you revise important equations, understand relationships between physical quantities, and save time during revision.

This Class 12 Physics formula guide covers key formulas from all 14 chapters prescribed in the CBSE Physics syllabus for the 2026–27 academic session. Use it alongside your NCERT textbook, classroom notes, solved examples, and practice questions.

Important: This is a quick-revision guide, not a substitute for the complete NCERT syllabus. Check your current syllabus and textbook for detailed concepts, derivations, conditions, and deleted or revised topics.

Class 12 Physics Formula Sheet: Chapter-Wise Revision

Chapter 1: Electric Charges and Fields

Coulomb’s Law

F = (1 / 4πε₀) × |q₁q₂| / r²

Electric Field

E = F / q

Electric Field Due to a Point Charge

E = (1 / 4πε₀) × |q| / r²

Electric Dipole Moment

p = q × 2a

Electric Flux

ΦE = E A cos θ

Gauss’s Law

∮ E · dA = qₑₙ꜀ₗ / ε₀

Remember that electric field and force are vector quantities. Pay attention to direction, signs, and the geometry of the charge distribution when solving numerical problems.

Chapter 2: Electrostatic Potential and Capacitance

Electric Potential

V = W / q

Potential Due to a Point Charge

V = (1 / 4πε₀) × q / r

Relation Between Electric Field and Potential

E = −dV/dr

Capacitance

C = Q / V

Parallel-Plate Capacitor in Vacuum

C = ε₀A / d

Capacitors in Parallel

Ceq = C₁ + C₂ + C₃ + …

Capacitors in Series

1/Ceq = 1/C₁ + 1/C₂ + 1/C₃ + …

Energy Stored in a Capacitor

U = ½CV² = Q²/(2C) = ½QV

For numerical questions, identify whether the capacitors are connected in series or parallel before calculating equivalent capacitance.

Chapter 3: Current Electricity

Electric Current

I = Q/t

Ohm’s Law

V = IR

Resistance of a Uniform Conductor

R = ρL/A

Electrical Power

P = VI = I²R = V²/R

Resistors in Series

Req = R₁ + R₂ + R₃ + …

Resistors in Parallel

1/Req = 1/R₁ + 1/R₂ + 1/R₃ + …

Drift-Velocity Relation

I = neAvd

Here, ρ is resistivity, L is conductor length, A is cross-sectional area, n is the number density of charge carriers, and vd is drift velocity.

Also revise Kirchhoff’s rules, cells and internal resistance, and the Wheatstone bridge wherever included in your prescribed syllabus.

Chapter 4: Moving Charges and Magnetism

Magnetic Force on a Moving Charge

F = |q|vB sin θ

Magnetic Force on a Current-Carrying Conductor

F = BIL sin θ

Radius of Circular Motion in a Uniform Magnetic Field

r = mv / (|q|B)

This expression applies when the velocity is perpendicular to the magnetic field.

Magnetic Field Around a Long Straight Current-Carrying Wire

B = μ₀I / (2πr)

Magnetic Field at the Centre of a Circular Current Loop

B = μ₀NI / (2R)

Torque on a Current Loop

τ = NIAB sin θ

Revise the right-hand rule and the direction of magnetic force carefully. These are important when solving conceptual and numerical questions.

Chapter 5: Magnetism and Matter

Magnetic Dipole Moment of a Current Loop

m = NIA

Torque on a Magnetic Dipole

τ = mB sin θ

Potential Energy of a Magnetic Dipole

U = −m · B

Magnetic Susceptibility

χm = M/H

For a linear magnetic material, the relationship between magnetisation and magnetic field depends on the material and the convention used in the syllabus.

Revise the properties of diamagnetic, paramagnetic, and ferromagnetic materials, along with the relevant definitions and diagrams.

Chapter 6: Electromagnetic Induction

Magnetic Flux

ΦB = BA cos θ

This expression applies to a uniform magnetic field over a flat area.

Faraday’s Law of Induction

ε = −N(dΦB/dt)

Motional EMF

ε = Blv

This form applies when the conductor moves perpendicular to the magnetic field and its length.

Self-Inductance

ε = −L(dI/dt)

The negative sign in Faraday’s law represents Lenz’s law: the induced effect opposes the change in magnetic flux that produces it.

Chapter 7: Alternating Current

Instantaneous Alternating Voltage

V = V₀ sin ωt

RMS Voltage

Vrms = V₀/√2

RMS Current

Irms = I₀/√2

These RMS relations apply to a sinusoidal alternating current or voltage.

Inductive Reactance

XL = ωL

Capacitive Reactance

XC = 1/(ωC)

Impedance of a Series LCR Circuit

Z = √[R² + (XL − XC)²]

Resonant Angular Frequency

ω₀ = 1/√(LC)

Average Power in an AC Circuit

P = Vrms Irms cos φ

Revise the phase difference, power factor, resonance, and transformer principles along with the formulas.

Chapter 8: Electromagnetic Waves

Wave Speed

c = νλ

Relation Between Electric and Magnetic Field Amplitudes in a Vacuum

E₀ = cB₀

Here, c is the speed of light in vacuum, ν is frequency, and λ is wavelength.

Understand the electromagnetic spectrum in order, along with the uses and basic properties of radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Chapter 9: Ray Optics and Optical Instruments

Mirror Formula

1/f = 1/v + 1/u

Magnification for a Spherical Mirror

m = −v/u

Thin-Lens Formula

1/f = 1/v − 1/u

Magnification for a Thin Lens

m = v/u

Power of a Lens

P = 1/f

For power in dioptres, use focal length in metres.

Refractive Index

n = c/v

Snell’s Law

n₁ sin i = n₂ sin r

Use the appropriate Cartesian sign convention consistently for mirrors and lenses. Also revise refraction, total internal reflection, optical instruments, and ray diagrams as required by your syllabus.

Chapter 10: Wave Optics

Path Difference for Constructive Interference

Δx = nλ

Path Difference for Destructive Interference

Δx = (n + ½)λ

These relations apply to ideal coherent sources, with n = 0, 1, 2, …

Young’s Double-Slit Experiment: Fringe Width

β = λD/d

Here, λ is wavelength, D is the distance to the screen, and d is the separation between the slits.

Single-Slit Diffraction: Approximate Width of the Central Maximum

W = 2λD/a

This approximation applies in the usual far-field setup, where a is the slit width.

Revise coherent sources, interference, diffraction, and the conditions under which the standard formulas apply.

Chapter 11: Dual Nature of Radiation and Matter

Photon Energy

E = hν = hc/λ

Einstein’s Photoelectric Equation

Kmax = hν − φ

Maximum Kinetic Energy of a Photoelectron

Kmax = eVs

Here, Vs is the stopping-potential magnitude.

de Broglie Wavelength

λ = h/p

For a non-relativistic particle of mass m and speed v:

λ = h/(mv)

Understand threshold frequency, work function, stopping potential, and the particle nature of radiation.

Chapter 12: Atoms

Bohr’s Quantised Angular Momentum

mvr = nh/(2π)

Radius of the nth Bohr Orbit for Hydrogen

rn = a₀n²

Energy of the nth Bohr Level for Hydrogen

En = −13.6/n² eV

The last two expressions are for the hydrogen atom in the Bohr model.

Photon Energy During a Transition

|ΔE| = hν = hc/λ

Revise the Bohr model, energy levels, and spectral transitions. Use the appropriate model and assumptions for the question being asked.

Chapter 13: Nuclei

Mass-Energy Equivalence

E = mc²

Mass Defect

Δm = (total mass of separated nucleons) − (mass of the nucleus)

Binding Energy

B.E. = Δmc²

If the mass defect is expressed in atomic mass units, use the appropriate conversion to obtain energy in electronvolts or mega-electronvolts.

Radioactive Decay Law

N = N₀e^(−λt)

Half-Life

T½ = 0.693/λ

Revise nuclear size, mass defect, binding energy per nucleon, nuclear fission, and nuclear fusion alongside these equations.

Chapter 14: Semiconductor Electronics

Conductivity of a Semiconductor

σ = e(nμe + pμh)

Here, n and p represent electron and hole concentrations, while μe and μh represent their respective mobilities.

Diode Current-Voltage Relationship

I = I₀(e^(V/ηVT) − 1)

This is the idealised Shockley diode equation; the parameters depend on the device and operating conditions. Follow the level and scope of your prescribed syllabus.

Focus on semiconductor basics, p-type and n-type materials, p-n junction behaviour, and diode characteristics as covered in your textbook.

How to Use a Class 12 Physics Formula Sheet Effectively

1. Revise by chapter: Study one chapter’s formulas at a time instead of memorising the entire list in one sitting.

2. Understand each symbol: Know the meaning and SI unit of every physical quantity.

3. Practise numerical questions: Apply each formula to textbook examples and previous practice questions.

4. Check conditions and sign conventions: A formula may depend on assumptions, geometry, or the chosen sign convention.

5. Revise regularly: Return to difficult formulas and incorrect questions throughout your preparation.

6. Use the current syllabus: Check the official CBSE curriculum for the academic year you are studying.

Where to Find Class 12 Physics Notes and Formula Sheets

Looking for additional revision resources? Explore the study materials available on NCERTGuides:

• Browse Class 12 Study Notes

• Explore Formula Sheets

Before purchasing any digital study resource, review its product description, sample pages, chapter coverage, file format, and price to ensure it matches your requirements.

For the official course structure, consult the CBSE Class 12 Physics syllabus for 2026–27.

Frequently Asked Questions

1. Where can I find a Class 12 Physics formula sheet PDF?

You can explore formula sheets and revision resources in the NCERTGuides Formula Sheets collection. Check the individual product page for format, coverage, sample pages, and pricing.

2. How many chapters are included in the CBSE Class 12 Physics syllabus for 2026–27?

The official CBSE Physics syllabus lists 14 chapters organised into nine units. Always consult the official syllabus for the current academic session.

3. Is a formula sheet enough to prepare for the Physics board exam?

No. A formula sheet is useful for revision, but you should also study concepts, derivations, diagrams, solved examples, and practice questions from the prescribed syllabus.

4. How should I memorise Physics formulas?

Understand the physical meaning of each formula, note the units, practise applying it to numerical questions, and revisit formulas you frequently forget.

5. Does every formula apply to every situation?

No. Some formulas require specific assumptions, such as uniform fields, idealised models, small-angle approximations, or particular sign conventions. Check the conditions before using a formula.

Final Revision Tip

A formula becomes easier to remember when you understand what it describes and practise using it. Combine chapter-wise formula revision with NCERT study and regular problem-solving for more effective Class 12 Physics preparation.