Class 10 Physics Notes — All Chapters with Formulas & Solved Numericals (2026)
Complete class 10 physics notes for Pakistani board exams. Key definitions, all formulas, and important solved numericals for every chapter.
These class 10 physics notes cover all eight chapters (Chapters 10–17) of the Punjab Board, Federal Board, and KPK Board syllabus. Each section includes the definitions, formulas, and key concepts you need for board exam revision.
Chapter 10: Simple Harmonic Motion and Waves
Key formulas:
- Time period of simple pendulum: T = 2π√(l/g)
- Frequency: f = 1/T
- Wave equation: v = fλ
- Relationship: v = λ/T
Key concepts: SHM is motion where restoring force is proportional to displacement (F = −kx). Transverse waves: particles vibrate perpendicular to wave direction (e.g., light). Longitudinal waves: particles vibrate parallel to wave direction (e.g., sound).
Chapter 11: Sound
Key formulas:
- Speed of sound = distance / time
- Echo minimum distance: d = v × t/2 (minimum 17 m for distinct echo at 340 m/s, t = 0.1s)
Key concepts: Sound requires a medium (cannot travel through vacuum). Speed: solids > liquids > gases. Loudness depends on amplitude; pitch depends on frequency; quality depends on waveform (harmonics).
Chapter 12: Geometrical Optics
Key formulas:
- Mirror formula: 1/f = 1/p + 1/q
- Lens formula: 1/f = 1/p + 1/q
- Magnification: M = q/p = image height / object height
- Snell's law: n₁ sin θ₁ = n₂ sin θ₂
- Refractive index: n = c/v = sin i / sin r
- Critical angle: sin θc = 1/n (for total internal reflection)
- Power of lens: P = 1/f (in dioptres, when f is in metres)
Sign convention: All distances measured from the optical centre/pole. Distances in the direction of incident light are positive. Focal length: positive for convex lens/concave mirror, negative for concave lens/convex mirror.
Board tip: Always draw ray diagrams for mirror and lens questions. Use at least two rays to locate the image.
Chapter 13: Electrostatics
Key formulas:
- Coulomb's law: F = kq₁q₂/r² where k = 9 × 10⁹ Nm²/C²
- Electric field: E = F/q = kQ/r²
- Electric potential: V = W/q (SI unit: volt)
- Capacitance: C = Q/V (SI unit: farad)
- Energy stored in capacitor: E = ½CV² = ½QV = Q²/2C
Key concepts: Like charges repel, unlike charges attract. Electric field lines go from positive to negative. Capacitors in parallel: C_total = C₁ + C₂. Capacitors in series: 1/C_total = 1/C₁ + 1/C₂.
Chapter 14: Current Electricity
Key formulas:
- Ohm's law: V = IR
- Series resistance: R_total = R₁ + R₂ + R₃
- Parallel resistance: 1/R_total = 1/R₁ + 1/R₂ + 1/R₃
- Electrical power: P = VI = I²R = V²/R
- Electrical energy: E = Pt = VIt
- Cost of electricity: Energy (kWh) × rate per unit
Board tip: For circuit problems, first identify which resistors are in series and which are in parallel. Calculate total resistance, then use V = IR to find current. This systematic approach solves 90% of circuit numericals.
Chapter 15: Electromagnetism
Key formulas:
- Force on conductor: F = BIL (when current is perpendicular to field)
- Transformer equation: Vp/Vs = Np/Ns = Is/Ip
- Transformer efficiency: η = (Vs × Is)/(Vp × Ip) × 100%
Key rules: Right-hand grip rule (magnetic field around a wire). Fleming's left-hand rule (motor effect: force on current in magnetic field). Fleming's right-hand rule (generator: induced EMF direction).
Chapter 16: Basic Electronics
Key concepts:
- p-type semiconductor: Doped with trivalent element (e.g., boron) — majority carriers are holes
- n-type semiconductor: Doped with pentavalent element (e.g., phosphorus) — majority carriers are electrons
- Diode: Forward bias: current flows. Reverse bias: no current (until breakdown)
- Logic gates: AND (both inputs high → output high), OR (any input high → output high), NOT (inverts input), NAND (NOT + AND), NOR (NOT + OR)
Chapter 17: Information and Communication Technology
Key concepts: Analogue signals are continuous; digital signals are discrete (0 and 1). Components of a communication system: information source → transmitter → channel → receiver → destination. Optical fibres use total internal reflection to transmit data as light pulses.
Revision Strategy
Use these notes for quick revision, not first-time learning. After revising, test yourself with MCQs on HighYield — if you score below 70% on any chapter, go back to the textbook for that chapter before moving on.