NEET Physics Formula Sheet

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Complete Chapter-wise Formulas for Class 11 & 12 — Quick Revision for NEET

📐 Class 11 Physics Mechanics & Waves

Units & Measurements

Error Analysis

ΔZ/Z = ΔA/A + ΔB/B

For Z = A × B or A ÷ B

Relative error

Error in Power

ΔZ/Z = n(ΔA/A)

For Z = Aⁿ

n = exponent

Dimensional Formula

[F] = [MLT⁻²]

Force = Mass × Acceleration

SI unit: N

Kinematics (Motion in a Line & Plane)

1st Equation

v = u + at

Final velocity

Constant acceleration

2nd Equation

s = ut + ½at²

Displacement

Constant acceleration

3rd Equation

v² = u² + 2as

Velocity-displacement relation

Constant acceleration

Projectile: Time of Flight

T = 2u sinθ / g

Total flight time

Same level projection

Projectile: Max Height

H = u² sin²θ / 2g

Maximum height reached

Same level projection

Projectile: Range

R = u² sin2θ / g

Horizontal range

Max at θ = 45°

Centripetal Acceleration

a_c = v²/r = rω²

Uniform circular motion

Directed towards centre

Relative Velocity

v_AB = v_A − v_B

Velocity of A relative to B

Vector subtraction

Laws of Motion

Newton's 2nd Law

F = ma

Net force = mass × acceleration

SI unit: N

Momentum

p = mv

Linear momentum

Vector quantity

Impulse

J = F·Δt = Δp

Change in momentum

Area under F-t graph

Static Friction

f_s ≤ μ_sN

Limiting friction

Self-adjusting up to limit

Kinetic Friction

f_k = μ_kN

Sliding friction

μ_k < μ_s

Angle of Repose

tanθ = μ

Object just begins to slide

On inclined plane

Centripetal Force

F_c = mv²/r

Required for circular motion

Directed towards centre

Work, Energy & Power

Work

W = F·d·cosθ

Work done by constant force

θ = angle between F and d

Kinetic Energy

KE = ½mv²

Energy due to motion

Always positive

Gravitational PE

PE = mgh

Near earth's surface

h << R_e

Spring PE

PE = ½kx²

Elastic potential energy

Hooke's law: F = −kx

Work-Energy Theorem

W_net = ΔKE

Net work = change in KE

Valid for all forces

Power

P = W/t = F·v

Rate of doing work

SI unit: Watt (W)

Elastic Collision (1D)

v₁ = (m₁−m₂)u₁/(m₁+m₂)

Final velocity of m₁

m₂ initially at rest

Rotational Motion

Torque

τ = r × F

Moment of force

SI unit: N·m

Angular Momentum

L = Iω = r × p

Rotational analogue of momentum

Conserved if τ_ext = 0

Moment of Inertia (Ring)

I = MR²

About axis through centre

Perpendicular to plane

Moment of Inertia (Disc)

I = ½MR²

About central axis

Perpendicular to plane

Moment of Inertia (Rod)

I = ML²/12

About centre, perpendicular to rod

Uniform rod

Parallel Axis Theorem

I = I_cm + Md²

Moment of inertia about any axis

d = distance from CM

Rotational KE

K = ½Iω²

Kinetic energy of rotation

Analogous to ½mv²

Gravitation

Universal Law

F = G·M·m/r²

Gravitational force

G = 6.67 × 10⁻¹¹ N·m²/kg²

Gravitational Field

E = GM/r²

Force per unit mass

Radial outward from mass

Gravitational Potential

V = −GM/r

Potential energy per unit mass

Zero at infinity

Escape Velocity

v_e = √(2GM/R)

Minimum speed to escape

≈ 11.2 km/s on Earth

Orbital Velocity

v_o = √(GM/r)

Satellite in circular orbit

v_o = v_e/√2

Kepler's 3rd Law

T² ∝ r³

T²/r³ = constant

For planets around Sun

Oscillations & Waves

SHM: Time Period (Spring)

T = 2π√(m/k)

Spring-mass system

Simple harmonic motion

SHM: Time Period (Pendulum)

T = 2π√(L/g)

Simple pendulum

Small oscillations

Wave Speed

v = fλ

Speed = frequency × wavelength

For all waves

Standing Waves (String)

f_n = n·v/2L

n = 1, 2, 3,...

n = 1 is fundamental

Doppler Effect (Approach)

f' = f(v+v_o)/(v−v_s)

Observer & source approaching

v = speed of sound

⚡ Class 12 Physics Electrostatics, Optics & Modern Physics

Electrostatics

Coulomb's Law

F = k·q₁q₂/r²

Force between two charges

k = 9 × 10⁹ N·m²/C²

Electric Field (Point Charge)

E = k·Q/r²

Field due to point charge

Radial outward/inward

Electric Flux

Φ = E·A·cosθ

Gauss's law: Φ = q_enc/ε₀

ε₀ = 8.85 × 10⁻¹²

Electric Dipole Moment

p = q·2a

Dipole moment vector

From −q to +q

Dipole Axial Field

E = 2kp/r³

Field along dipole axis

r >> a

Dipole Equatorial Field

E = kp/r³

Field perpendicular to axis

r >> a

Potential (Point Charge)

V = kQ/r

Electric potential

Zero at infinity

Capacitance (Parallel Plate)

C = ε₀A/d

Capacitance with dielectric: C = Kε₀A/d

K = dielectric constant

Energy in Capacitor

U = ½CV² = Q²/2C

Stored energy

Energy density: u = ½ε₀E²

Capacitors in Series

1/C_eq = 1/C₁ + 1/C₂ + ...

Equivalent capacitance

Same charge on each

Capacitors in Parallel

C_eq = C₁ + C₂ + ...

Equivalent capacitance

Same potential difference

Current Electricity

Ohm's Law

V = IR

Potential difference = Current × Resistance

Ohmic conductors only

Resistance

R = ρ·L/A

Resistivity: ρ = 1/σ

L = length, A = area

Temperature Dependence

ρ = ρ₀(1 + αΔT)

Resistivity change with temp

α = temperature coefficient

Drift Velocity

v_d = I/(n·A·e)

Average velocity of electrons

n = charge density

Power

P = VI = I²R = V²/R

Electrical power

SI unit: W

Resistors in Series

R_eq = R₁ + R₂ + ...

Equivalent resistance

Same current

Resistors in Parallel

1/R_eq = 1/R₁ + 1/R₂ + ...

Equivalent resistance

Same voltage

Kirchhoff's Laws

ΣI_in = ΣI_out; ΣV = 0

Junction & Loop rules

KCL & KVL

Wheatstone Bridge

P/Q = R/S

Balanced condition

Galvanometer shows zero

EMF & Internal Resistance

V = ε − Ir

Terminal voltage

r = internal resistance

Magnetism

Biot-Savart Law

dB = μ₀·I·dl·sinθ/(4πr²)

Magnetic field due to current element

μ₀ = 4π × 10⁻⁷

B: Infinite Wire

B = μ₀I/(2πr)

Magnetic field around wire

r = perpendicular distance

B: Circular Loop (Centre)

B = μ₀I/(2R)

Field at centre of loop

R = radius of loop

B: Solenoid

B = μ₀·n·I

Inside ideal solenoid

n = turns per unit length

Force on Moving Charge

F = q·v×B

Lorentz force

F = qvB sinθ

Force on Current Wire

F = I·L×B

Magnetic force on conductor

F = BIL sinθ

Torque on Loop

τ = N·I·A·B·sinθ

Torque = Magnetic moment × B

M = NIA

Bar Magnet: Axial Field

B = μ₀·2M/(4πr³)

Field along dipole axis

r >> length

Bar Magnet: Equatorial

B = μ₀·M/(4πr³)

Field perpendicular to axis

r >> length

Magnetic Susceptibility

χ = μ_r − 1

χ < 0: diamagnetic; χ > 0: paramagnetic

Ferromagnetic: χ >> 1

EMI & AC

Magnetic Flux

Φ = B·A·cosθ

Flux through area

Unit: Weber (Wb)

Faraday's Law

ε = −N·dΦ/dt

Induced EMF

N = number of turns

Motional EMF

ε = B·L·v

Rod moving in magnetic field

v ⊥ B

RMS Value (AC)

I_rms = I₀/√2

Root mean square current

For sinusoidal AC

Inductive Reactance

X_L = ωL

Resistance of inductor

ω = 2πf

Capacitive Reactance

X_C = 1/(ωC)

Resistance of capacitor

ω = 2πf

LCR Impedance

Z = √(R² + (X_L − X_C)²)

Total opposition in AC circuit

At resonance: X_L = X_C

Transformer

V_s/V_p = N_s/N_p

Voltage ratio

Ideal transformer

Optics

Mirror Formula

1/f = 1/v + 1/u

Spherical mirror

Sign convention: REAL

Lens Formula

1/f = 1/v − 1/u

Thin lens

Lens maker's: 1/f = (μ−1)(1/R₁−1/R₂)

Magnification (Mirror/Lens)

m = h_i/h_o = −v/u

Lateral magnification

m > 0: virtual image

Power of Lens

P = 1/f (in metres)

Optical power in dioptres

P = P₁ + P₂ for combination

Snell's Law

sin i/sin r = n₂/n₁ = v₁/v₂

Refraction of light

n = refractive index

Apparent Depth

d' = d/n_relative

At near-normal incidence

n_rel = n₂/n₁

Prism: δ_min

μ = sin[(A+δ_m)/2] / sin(A/2)

Minimum deviation angle

A = prism angle

YDSE: Fringe Width

β = λD/d

Interference fringe width

D = screen distance, d = slit separation

Diffraction: Central Max

θ = λ/a

First minimum angle

a = slit width

Magnifying Power

M = (1 + D/f) for simple microscope

Angular magnification

D = near point (25 cm)

Modern Physics

Photoelectric Effect

E = hν = W + KE_max

Einstein's photoelectric equation

h = 6.626 × 10⁻³⁴ J·s

Threshold Frequency

ν₀ = W/h

Minimum frequency to eject electron

W = work function

Stopping Potential

eV₀ = KE_max

Potential to stop photoelectrons

V₀ = stopping potential

de Broglie Wavelength

λ = h/p = h/(mv)

Matter wave of particle

For electron: λ = √(150/V) Å

Bohr Model: Energy

E_n = −13.6/n² eV

Energy levels of hydrogen

n = 1, 2, 3...

Bohr Model: Radius

r_n = n²·0.529 Å

Orbit radius of hydrogen

n = 1, 2, 3...

Mass-Energy Equivalence

E = mc²

Einstein's famous equation

m = mass defect

Binding Energy

BE = Δm·c²

Energy to break nucleus

Δm = mass defect

Radioactive Decay

N = N₀·e^−λt

Number of nuclei remaining

λ = decay constant

Half-Life

T_½ = ln2/λ = 0.693/λ

Time for half decay

Independent of initial amount

🔢 Key Constants for NEET

Speed of Light

c = 3 × 10⁸ m/s

Planck's Constant

h = 6.626 × 10⁻³⁴ J·s

Gravitational Constant

G = 6.67 × 10⁻¹¹ N·m²/kg²

Coulomb's Constant

k = 9 × 10⁹ N·m²/C²

Permittivity (Free Space)

ε₀ = 8.85 × 10⁻¹² C²/N·m²

Permeability (Free Space)

μ₀ = 4π × 10⁻⁷ T·m/A

Electron Charge

e = 1.6 × 10⁻¹⁹ C

Electron Mass

m_e = 9.11 × 10⁻³¹ kg

Avogadro's Number

N_A = 6.022 × 10²³ mol⁻¹

Gas Constant

R = 8.314 J·mol⁻¹·K⁻¹

Boltzmann Constant

k_B = 1.38 × 10⁻²³ J/K

1 eV

1 eV = 1.6 × 10⁻¹⁹ J