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JEE Main physics formula sheet, unit by unit

Every core JEE Main physics formula in one place, arranged by the units of the official 2026 syllabus, with the condition each one needs and the results that are no longer in the syllabus left out.

21 Oct 2026 11 min read

In this guide
  1. Units, measurement and experimental skills
  2. Kinematics
  3. Laws of motion and friction
  4. Work, energy, power and collisions
  5. Centre of mass and rotation
  6. Gravitation
  7. Properties of solids and liquids, and heat
  8. Thermodynamics and kinetic theory
  9. Oscillations and waves
  10. Electrostatics and capacitors
  11. Current electricity
  12. Magnetism, EMI and AC
  13. Optics
  14. Modern physics and electronic devices
  15. How to use this sheet

A formula sheet is only useful if it tells you when a formula works. Most wrong answers in JEE Main physics come from a correct formula used in the wrong situation, so each table below has a column for the condition. Use it for quick revision, not as a first introduction; every chapter has its own guide with derivations and worked problems.

The sheet follows the units of the official 2026 syllabus. Symbols are standard: k = 1/4πε₀ ≈ 9 × 10⁹ N m² C⁻², hc ≈ 1240 eV nm, 1 u ≈ 931.5 MeV.

Units, measurement and experimental skills

FormulaNote
Relative error of z = aᵖbᵐ/cⁿ: Δz/z = pΔa/a + mΔb/b + nΔc/cErrors always add, even for division
Δ(a ± b) = Δa + ΔbAbsolute errors add for sums and differences
Vernier least count = 1 MSD − 1 VSDSubtract the zero error with its sign
Screw gauge least count = pitch/number of circular divisionsSame zero-error rule

Kinematics

FormulaNote
v = u + at, s = ut + ½at², v² = u² + 2asConstant acceleration only
Distance in the nth second = u + a(2n − 1)/2Constant acceleration
T = 2u sin θ/g, H = u² sin²θ/2g, R = u² sin 2θ/gLevel ground, no air resistance
R_max = u²/g at θ = 45°Angles θ and 90° − θ give the same range
y = x tan θ − gx²/(2u² cos²θ)Trajectory equation
Relative velocity v_AB = v_A − v_BVector subtraction
a_c = v²/r = ω²rUniform circular motion

Laws of motion and friction

FormulaNote
F = dp/dt; impulse J = FΔt = ΔpNewton's second law in general form
f_s ≤ μ_s N, f_k = μ_k NStatic friction adjusts up to its limit
Angle of repose: tan θ = μ_sBlock about to slide
Level road: v_max = √(μrg)Friction provides the centripetal force
Banked road, no friction: tan θ = v²/rgWith friction, v_max = √[rg(μ + tan θ)/(1 − μ tan θ)]
Atwood: a = (m₁ − m₂)g/(m₁ + m₂), T = 2m₁m₂g/(m₁ + m₂)Light string, frictionless pulley

Work, energy, power and collisions

FormulaNote
W = F·s = Fs cos θ; W = ∫F dxVariable force: integrate
W_net = ΔK (work–energy theorem)Includes work by all forces
P = dW/dt = F·vInstantaneous power
Spring: U = ½kx²x from natural length
Vertical circle (string): v_top ≥ √(gr), v_bottom ≥ √(5gr)Tension difference T_bottom − T_top = 6mg
e = (velocity of separation)/(velocity of approach)e = 1 elastic, e = 0 perfectly inelastic
1-D elastic, m₂ at rest: v₁ = (m₁ − m₂)u₁/(m₁ + m₂), v₂ = 2m₁u₁/(m₁ + m₂)Equal masses exchange velocities
KE lost in perfectly inelastic collision = m₁m₂(u₁ − u₂)²/[2(m₁ + m₂)]Momentum is still conserved

Centre of mass and rotation

FormulaNote
x_cm = Σmᵢxᵢ/ΣmᵢFor a cut-out, treat the hole as negative mass
τ = r × F = IαAbout a fixed axis or the centre of mass
L = Iω; if τ_ext = 0, I₁ω₁ = I₂ω₂KE is not conserved in general
KE_rot = ½Iω²; I = Mk²k is the radius of gyration
Parallel axis: I = I_cm + Md²Axes must be parallel, one through the CM
Perpendicular axis: I_z = I_x + I_yPlanar bodies only
Ring MR², disc ½MR², solid sphere ⅖MR², hollow sphere ⅔MR²About a central axis (diameter for spheres)
Rod: ML²/12 about the centre, ML²/3 about one endAxis perpendicular to the rod

Gravitation

FormulaNote
F = Gm₁m₂/r², g = GM/R²Point masses or spheres
g_h = gR²/(R + h)² ≈ g(1 − 2h/R)Approximation for h much smaller than R
g_d = g(1 − d/R)Uniform Earth; g = 0 at the centre
U = −GMm/r, V = −GM/rZero at infinity
v_e = √(2GM/R) = √(2gR)Independent of the launch direction
v_o = √(GM/r), T² = 4π²r³/GMCircular orbit of radius r
Satellite energy E = −GMm/2r; KE = GMm/2rE = −KE

Properties of solids and liquids, and heat

FormulaNote
Y = (F/A)/(ΔL/L); B = −ΔP/(ΔV/V)Within the elastic limit
Elastic energy per volume = ½ × stress × strainEnergy stored = ½F ΔL
P = P₀ + ρghStatic fluid
Stokes: F = 6πηrv; terminal velocity v_t = 2r²(ρ − σ)g/9ηSmall sphere, streamline flow
A₁v₁ = A₂v₂; P + ½ρv² + ρgh = constantIncompressible, non-viscous, streamline flow
Efflux speed v = √(2gh)h below the free surface
Reynolds number Re = ρvD/ηLow Re: streamline; high Re: turbulent
Excess pressure: drop 2T/r, soap bubble 4T/rA bubble has two surfaces
Capillary rise h = 2T cos θ/(rρg)θ is the angle of contact
ΔL = LαΔT, β = 2α, γ = 3αIsotropic solid
Q = mcΔT; Q = mLCalorimetry: heat lost = heat gained
Conduction: H = KAΔT/L; thermal resistance L/KASteady state

Thermodynamics and kinetic theory

FormulaNote
ΔU = Q − WPhysics convention: W is work done by the gas
W = ∫P dV; isothermal W = nRT ln(V₂/V₁)Reversible processes
Adiabatic: PVᵞ = constant, W = (P₁V₁ − P₂V₂)/(γ − 1)Q = 0
ΔU = nC_vΔTAny process, ideal gas
C_p − C_v = R, γ = C_p/C_v = 1 + 2/fPer mole
Heat engine efficiency η = W/Q₁ = 1 − Q₂/Q₁Q₂ is heat rejected
P = ⅓ρv_rms², v_rms = √(3RT/M)M in kg/mol
Average KE per molecule = (3/2)k_BT; U = (f/2)nRTEquipartition: ½k_BT per degree of freedom
Mean free path λ = 1/(√2 πd²n)n = number density

Oscillations and waves

FormulaNote
x = A sin(ωt + φ), v = ω√(A² − x²), a = −ω²xSHM
Spring: T = 2π√(m/k); pendulum: T = 2π√(l/g)Pendulum: small angles
Springs in series 1/k = 1/k₁ + 1/k₂; parallel k = k₁ + k₂Same extension in parallel, same force in series
Energy E = ½kA² = ½mω²A²Constant in SHM
y = A sin(kx − ωt), v = ω/k = fλWave travelling in +x
String: v = √(T/μ); gas: v = √(γP/ρ)μ = mass per unit length
String fixed at both ends or open pipe: fₙ = nv/2LAll harmonics
Closed pipe: f = (2n − 1)v/4LOdd harmonics only
Resonance tube: λ/2 = L₂ − L₁End correction cancels
Beat frequency = f₁ − f₂Audible only for a small difference

Electrostatics and capacitors

FormulaNote
F = kq₁q₂/r², E = kq/r², V = kq/rPoint charges
Dipole: E_axial = 2kp/r³, E_equatorial = kp/r³r much larger than the dipole length
τ = p × E, U = −p·EUniform field
Gauss: Φ = q_enclosed/ε₀Any closed surface
Line charge E = λ/2πε₀r; sheet E = σ/2ε₀Infinite wire and plane sheet
Thin shell: E = kQ/r² outside, 0 insideV = kQ/R everywhere inside
E = −dV/dr; U = kq₁q₂/rField points towards falling potential
C = ε₀A/d; with dielectric filling the gap, C = Kε₀A/dParallel plates
Series 1/C = 1/C₁ + 1/C₂; parallel C = C₁ + C₂Series: same charge; parallel: same voltage
U = ½CV² = Q²/2C = ½QV; energy density ½ε₀E²Q fixed if the battery is removed
Common potential V = (C₁V₁ + C₂V₂)/(C₁ + C₂)Charge is shared; some energy is lost

Current electricity

FormulaNote
I = neAv_d, μ = v_d/EDrift velocity and mobility
R = ρL/A; R_T = R₀(1 + αΔT)Stretched wire: R ∝ L²
I = E/(R + r); V = E − IrDischarging cell
P = VI = I²R = V²/R; P_max at R = rMaximum power transfer
Wheatstone balance: P/Q = R/SNo current in the galvanometer
Metre bridge: R/S = l/(100 − l)l in cm

Magnetism, EMI and AC

FormulaNote
Long wire B = μ₀I/2πr; loop centre B = μ₀I/2RN turns: multiply by N
Loop axis B = μ₀IR²/[2(R² + x²)√(R² + x²)]Distance x from the centre
Solenoid B = μ₀nIn = turns per metre
F = q(E + v × B); r = mv/qB; T = 2πm/qBT is independent of speed
F = IL × B; parallel wires F/L = μ₀I₁I₂/2πdLike currents attract
τ = NIAB sin θ = m × Bm = NIA
Ammeter shunt S = I_gG/(I − I_g); voltmeter series R = V/I_g − GG = galvanometer resistance
Bar magnet: B_axial = μ₀2m/4πr³, B_equatorial = μ₀m/4πr³Far from the magnet
ε = −dΦ/dt; rod ε = Blv; rotating rod ε = ½Bωl²Lenz's law gives the direction
ε = −L dI/dt; U = ½LI²; solenoid L = μ₀n²AlAl is the solenoid's volume
AC generator ε = NBAω sin ωtPeak emf NBAω
I_rms = I₀/√2; X_L = ωL; X_C = 1/ωCSinusoidal AC
Z = √[R² + (X_L − X_C)²], tan φ = (X_L − X_C)/RSeries LCR
Resonance ω₀ = 1/√(LC); P = V_rms I_rms cos φcos φ is the power factor
Ideal transformer: V_s/V_p = N_s/N_p = I_p/I_sNo losses; power in = power out
c = 1/√(μ₀ε₀); E₀ = cB₀; I_d = ε₀ dΦ_E/dtEM waves; displacement current

Optics

FormulaNote
Mirror 1/v + 1/u = 1/f, f = R/2, m = −v/uCartesian signs
Lens 1/v − 1/u = 1/f, m = v/u, P = 1/f (f in m)Power in dioptres
Lens maker: 1/f = (n − 1)(1/R₁ − 1/R₂)In air
Lenses in contact: 1/f = 1/f₁ + 1/f₂Powers add
sin C = 1/nDenser to rarer medium
Prism: A = r₁ + r₂, δ = i + e − A; n = sin[(A + δ_m)/2]/sin(A/2)Thin prism: δ = (n − 1)A
Microscope m ≈ (L/f_o)(D/f_e); telescope m = f_o/f_eFinal image at infinity
Fringe width β = λD/dYoung's double slit
I = I₁ + I₂ + 2√(I₁I₂) cos φEqual intensities: 4I₀ cos²(φ/2)
Single slit minima a sin θ = nλ; central maximum width 2λD/aCentral maximum is twice the width of the others
Brewster: tan i_B = n; Polaroid: I = I₀ cos²θUnpolarised light is halved by the first Polaroid

Modern physics and electronic devices

FormulaNote
E = hν = hc/λ; E (eV) = 1240/λ (nm)Photon energy
KE_max = hν − φ = eV₀Photocurrent depends on intensity, KE_max does not
λ = h/p = h/√(2mK); electron λ = 1.227/√V nmV in volts
Bohr: r = 0.529 n²/Z Å, E = −13.6 Z²/n² eVHydrogen-like species
1/λ = RZ²(1/n₁² − 1/n₂²); lines from level n = n(n − 1)/2R ≈ 1.097 × 10⁷ m⁻¹
Nuclear radius R = R₀∛A, R₀ ≈ 1.2 fmDensity is nearly constant
BE = Δm c², Δm = Zm_p + (A − Z)m_n − M1 u = 931.5 MeV
Half-wave output frequency f; full-wave 2fRectifiers
NAND = NOT(A AND B); NOR = NOT(A OR B)Universal gates

How to use this sheet

  • Cover the right-hand column and say each condition aloud; the conditions are what the exam tests.
  • Rewrite one unit's table from memory each day; compare and correct.
  • For any formula you cannot derive in two lines, go back to its chapter guide, for example current electricity or modern physics.
  • Read common physics mistakes alongside this sheet; most of them are about conditions.

A note on dates and numbers. Exam patterns, vacancies and schedules change from year to year. Always confirm the current details in the latest notification on the National Testing Agency website .

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