How many formulas are there in Class 12 Physics?

It depends on how you count them. The formula-heavy chapters are Electric Charges and Fields, Electrostatic Potential and Capacitance, Current Electricity, Moving Charges and Magnetism, Alternating Current and Ray Optics. Knowing how each formula is derived makes it much easier to recall in the exam.

Which Class 12 Physics units carry the most marks?

In CBSE's 2026-27 course structure the 70-mark theory paper is split as: Electrostatics and Current Electricity 16, Magnetic Effects of Current, Magnetism, EMI and AC 17, EM Waves and Optics 18, Dual Nature, Atoms and Nuclei 12, and Electronic Devices 7. Practicals carry another 30 marks.

Are Physics formulas given in the CBSE board exam?

No. CBSE does not provide a formula sheet, so you need to know the standard formulas. In derivation questions, examiners mark your steps, so a correct method earns marks even if you slip later on.

How do I memorise Physics formulas effectively?

(1) Derive each formula at least once. (2) Group related formulas, such as all capacitor formulas. (3) Solve a few numericals with each formula. (4) Keep a formula sheet and revise it daily. (5) Check units: if the dimensions don't match, the formula is wrong.

Are these formulas enough for JEE Main and NEET?

They are the NCERT foundation both exams build on, but JEE Main and NEET also test Class 11 Physics and ask harder applications. Some topics CBSE has dropped from its board syllabus may still appear in those exams, so check NTA's current syllabus for each exam.

Class 12 Physics Formulas — Chapter-Wise

This is the complete Class 12 Physics formula list, chapter by chapter, following the 14 chapters of the NCERT textbooks that CBSE and many state boards use. Rows marked “not in CBSE 2026-27” are topics CBSE no longer assesses in the Board exam; other boards and entrance exams may still use them.

Chapter 1: Electric Charges and Fields

Formula	Description
F = kq₁q₂/r², k = 1/4πε₀ ≈ 9 × 10⁹ N m²/C²	Coulomb's law
E = F/q = kQ/r²	Electric field due to a point charge
p = q × 2a	Dipole moment (charges ±q, separation 2a)
E (axial) = 2kp/r³	Dipole field on the axis (r ≫ a)
E (equatorial) = kp/r³	Dipole field on the equatorial line (r ≫ a), opposite to p
τ = pE sinθ	Torque on a dipole in a uniform field
Φ = ∮E·dA = q_enclosed/ε₀	Gauss's law
E = λ/2πε₀r	Infinitely long straight wire (linear charge density λ)
E = σ/2ε₀	Infinite plane sheet of charge
E = kQ/r² outside, 0 inside	Thin spherical shell of charge Q

Chapter 2: Electrostatic Potential and Capacitance

Formula	Description
V = kQ/r	Potential due to a point charge
V = kp cosθ / r²	Potential due to a dipole
E = −dV/dr	Field from potential
W = qΔV	Work done moving a charge
U = kq₁q₂/r	Potential energy of two point charges
U = −pE cosθ	Potential energy of a dipole in a uniform field
C = Q/V	Capacitance
C = ε₀A/d; with dielectric C = Kε₀A/d	Parallel plate capacitor (K = dielectric constant)
Series: 1/C = 1/C₁ + 1/C₂ + …	Capacitors in series
Parallel: C = C₁ + C₂ + …	Capacitors in parallel
U = ½CV² = ½QV = Q²/2C	Energy stored in a capacitor (formulae only in CBSE)

Chapter 3: Current Electricity

Formula	Description
I = neAv_d	Current and drift velocity
v_d = eEτ/m; mobility μ = v_d/E	Drift velocity and mobility
V = IR; R = ρl/A; conductivity σ = 1/ρ	Ohm's law, resistivity and conductivity
ρ = ρ₀[1 + α(T − T₀)]	Temperature dependence of resistivity
P = VI = I²R = V²/R	Electric power
ε = V + Ir	emf, terminal voltage and internal resistance
Series cells: ε = ε₁ + ε₂, r = r₁ + r₂	Cells in series
Parallel cells: ε = (ε₁r₂ + ε₂r₁)/(r₁ + r₂), r = r₁r₂/(r₁ + r₂)	Cells in parallel
ΣI = 0 at a junction; Σε = ΣIR round a loop	Kirchhoff's rules
P/Q = R/S	Balanced Wheatstone bridge

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Chapter 4: Moving Charges and Magnetism

Formula	Description
F = q(v × B); \|F\| = qvB sinθ	Force on a moving charge
r = mv/qB	Radius of circular motion in a uniform field
F = I(l × B); \|F\| = BIl sinθ	Force on a current-carrying conductor
dB = (μ₀/4π) I dl sinθ / r²	Biot–Savart law
B = μ₀I/2R	Field at the centre of a circular loop
∮B·dl = μ₀I; B = μ₀I/2πr	Ampere's law; long straight wire
B = μ₀nI	Inside a long solenoid (qualitative only in CBSE)
F/l = μ₀I₁I₂/2πd	Force between two parallel currents (defines the ampere)
m = NIA; τ = NIAB sinθ	Magnetic moment of a loop and torque on it
Shunt S = I_gG/(I − I_g)	Galvanometer to ammeter
Series R = V/I_g − G	Galvanometer to voltmeter

Chapter 5: Magnetism and Matter

Formula	Description
χ = M/H	Magnetic susceptibility (M = magnetisation)
μᵣ = 1 + χ	Relative permeability
B (axial) = (μ₀/4π) 2m/r³; B (equatorial) = (μ₀/4π) m/r³	Field of a bar magnet. CBSE 2026-27 treats this qualitatively only

Chapter 6: Electromagnetic Induction

Formula	Description
Φ = BA cosθ	Magnetic flux
ε = −N dΦ/dt	Faraday's law (the minus sign is Lenz's law)
ε = Blv	Motional emf
ε = −L dI/dt; NΦ = LI	Self-induction
M = μ₀n₁n₂Al	Mutual inductance of two long coaxial solenoids
U = ½LI²	Energy stored in an inductor

Chapter 7: Alternating Current

Formula	Description
I_rms = I₀/√2; V_rms = V₀/√2	RMS values
X_L = ωL; X_C = 1/ωC	Inductive and capacitive reactance (ω = 2πf)
Z = √(R² + (X_L − X_C)²); tanφ = (X_L − X_C)/R	Series LCR impedance and phase
ω₀ = 1/√(LC); f₀ = 1/(2π√(LC))	Resonance
P = V_rms I_rms cosφ; power factor cosφ = R/Z	Average power
ε = NBAω sinωt	emf of an AC generator
V_s/V_p = N_s/N_p = I_p/I_s	Ideal transformer

Chapter 8: Electromagnetic Waves

Formula	Description
I_d = ε₀ dΦ_E/dt	Displacement current
c = 1/√(μ₀ε₀); c = νλ	Speed of EM waves in vacuum
E₀ = cB₀	Field amplitudes

Chapter 9: Ray Optics and Optical Instruments

Formula	Description
1/v + 1/u = 1/f; f = R/2	Mirror formula
m = −v/u	Magnification (mirror)
n₁ sinθ₁ = n₂ sinθ₂	Snell's law
sinC = 1/n	Critical angle (denser medium to air)
n₂/v − n₁/u = (n₂ − n₁)/R	Refraction at a spherical surface
1/v − 1/u = 1/f; m = v/u	Thin lens formula and magnification
1/f = (n − 1)(1/R₁ − 1/R₂)	Lens maker's formula
P = 1/f (f in metres); P = P₁ + P₂	Power, and thin lenses in contact
n = sin[(A + D_m)/2] / sin(A/2)	Prism at minimum deviation
m ≈ (L/f_o)(D/f_e)	Compound microscope, final image at infinity
m = f_o/f_e	Astronomical telescope, normal adjustment

Chapter 10: Wave Optics

Formula	Description
β = λD/d	Fringe width in Young's double-slit experiment (final expression only in CBSE)
Bright: path difference = nλ; dark: (2n − 1)λ/2	Interference conditions
Minima: a sinθ = nλ; central maximum width ≈ 2λD/a	Single-slit diffraction (qualitative in CBSE)
I = I₀ cos²θ; tanθ_p = n	Malus's and Brewster's laws. Not in CBSE 2026-27

Chapter 11: Dual Nature of Radiation and Matter

Formula	Description
E = hν = hc/λ	Energy of a photon
K_max = hν − φ₀ = eV₀	Einstein's photoelectric equation; V₀ = stopping potential
ν₀ = φ₀/h	Threshold frequency
λ = h/p = h/mv = h/√(2mK)	de Broglie wavelength

Chapter 12: Atoms

Formula (hydrogen-like atom)	Description
mvr = nh/2π	Bohr's quantisation condition
rₙ = 0.53 n²/Z Å	Radius of the nth orbit
vₙ ≈ 2.2 × 10⁶ Z/n m/s	Speed in the nth orbit
Eₙ = −13.6 Z²/n² eV	Energy of the nth orbit
1/λ = RZ²(1/n₁² − 1/n₂²)	Spectral lines (qualitative in CBSE)

Chapter 13: Nuclei

Formula	Description
R = R₀A^(1/3), R₀ ≈ 1.2 fm	Nuclear radius
Δm = [Zm_p + (A − Z)m_n] − M	Mass defect
E = mc²; BE = Δm × 931.5 MeV (Δm in u)	Binding energy
N = N₀e^(−λt); T½ = 0.693/λ; τ = 1/λ; A = λN	Radioactive decay. Not in CBSE 2026-27

Chapter 14: Semiconductor Electronics

Formula / fact	Description
n_e · n_h = n_i²	Carrier concentrations in a semiconductor at equilibrium
Half-wave rectifier: output frequency = input frequency; full-wave: twice the input frequency	Diode as a rectifier

Formulas are from the NCERT Class 12 Physics textbooks. Notes on what is and isn't assessed, and the unit marks, follow CBSE's 2026-27 syllabus; other boards differ, so check your own board's syllabus.

Class 12 Physics Formulas: Complete Chapter-Wise List