Do I need to memorise the formulas?

After understanding the concept, not before. Noting each quantity’s meaning and unit beside a formula makes it both memorable and usable.

No — each chapter uses the previous one’s concepts, so skipping strands you in the next.

When should I write the practical notebook?

On the day of the experiment, while it is fresh. Letting it pile up means a last-week rush and easy marks lost.

Class 9-10 Physics Book

বাংলায় পড়তে চাও? দেখো: নবম-দশম শ্রেণির পদার্থবিজ্ঞান বই

The commonest mistake in physics is memorising the formula first and hoping the concept follows. The order is the reverse — understand the concept and the formula becomes meaningful, and can be reconstructed even if forgotten.

The chapters

The book opens with physical quantities and measurement, then moves through motion, force, work and power, states of matter, heat, waves and sound, light, static and current electricity, magnetism, modern physics and science for saving life. The order is deliberate: each chapter uses the previous one’s concepts, so skipping leaves you stranded later.

Physics: learn it with interactive animations

An idea that is hard to picture from a still textbook diagram becomes obvious when you change the values yourself and watch it happen. Each simulation below comes with a full plain-language explanation, the formulas, solved examples, common mistakes and exam tips, so understanding and revision happen together.

Refraction of light (Grade 8–12 · animation)
Ohm's law (Grade 9–12 · animation)
Projectile motion (Grade 11 · animation)
Simple pendulum (Grade 9–11 · animation)
Electric field (Grade 10–12 · animation)
Wave interference (Grade 11–12 · animation)
Free Fall (Grade 9–11 · animation)
Lens ray diagrams (Grade 10–12 · animation)
Newton's Laws of Motion (Grade 9–11 · animation)
Spherical mirror ray diagrams (Grade 10–12 · animation)
Electromagnetic Induction (Grade 10–12 · animation)
Conservation of Momentum and Collisions (Grade 9–11 · animation)
Work, Energy and Power (Grade 9–11 · animation)
Inclined Plane (Grade 9–11 · animation)
Uniform circular motion (Grade 9–11 · animation)
Transverse and Longitudinal Waves (Grade 8–10 · animation)
Levers and moments (Grade 9–11 · animation)
Centre of mass (Grade 9–11 · animation)
Spring-mass SHM (Grade 9–11 · animation)
Vector addition: triangle and parallelogram laws (Grade 9–11 · animation)
Relative velocity: trains and river crossing (Grade 9–11 · animation)
Kepler's laws and elliptical orbits (Grade 11–12 · animation)
Newton’s law of gravitation, g and satellites (Grade 11–12 · animation)
Standing waves in strings and pipes (Grade 11–12 · animation)
Resonance tube and the speed of sound (Grade 11–12 · animation)
Beats: when two close notes pulse (Grade 11–12 · animation)
Doppler effect: moving sources, listeners and sonic booms (Grade 11–12 · animation)
Prism, dispersion of light and the rainbow (Grade 10–12 · animation)
Kirchhoff’s laws: junction rule and loop rule (Grade 11–12 · animation)
Wheatstone bridge and metre bridge (Grade 12 · animation)
Single-slit diffraction (Grade 11–12 · animation)
Defects of the human eye and their correction (Grade 10–12 · animation)
Polarisation of light: Malus’s law and Brewster’s law (Grade 12 · animation)
Charging and discharging a capacitor: the RC time constant (Grade 12 · animation)
Magnetic field lines: bar magnet, current-carrying wire and solenoid (Grade 10–12 · animation)
AC generator (Grade 12 · animation)
Transformer (Grade 10–12 · animation)
Heat transfer: conduction, convection and radiation (Grade 9–12 · animation)
Photoelectric effect: Einstein’s equation and the stopping potential (Grade 12 · animation)
Motor effect: force on a current-carrying wire and the DC motor (Grade 10–12 · animation)
Gas molecules and kinetic theory: pressure, temperature and speed (Grade 11–12 · animation)
The semiconductor diode: p–n junction, I–V curve and rectifier (Grade 12 · animation)
Radioactive decay: half-life, the decay law and penetration (Grade 10–12 · animation)
The Bohr atom: orbits, energy levels and the hydrogen spectrum (Grade 11–12 · animation)

Download the book

The core science-group textbook, in both versions.

The Bangla version and the English Version are different books — download the one matching your medium.

The formula-memorising trap

Unless you know what each quantity in a formula means and in what unit it is measured, the formula is a row of letters. When the paper turns the question slightly — changing which quantity is unknown — a memorised formula fails. Writing the meaning and unit of each quantity beside every formula removes the problem entirely.