The Journal

All articles

Every piece we've published, sorted by date. Each ends with worked problems and a FAQ.

Kirchhoff’s Laws (Current & Voltage)

Kirchhoff's law is two rules, not one: the current arriving at a junction equals the current leaving it, and the voltages around any closed loop sum to zero. This guide explains both with original diagrams, a clear sign convention, and 7 fully worked examples.

19 min read

Electromagnetism

What Is Electrical Resistance?

Electrical resistance measures how strongly a component opposes electric current: R = V/I, measured in ohms. This guide covers the four factors behind R = ρL/A, the resistance-versus-resistivity trap, seven worked problems and an interactive lab.

16 min read

Electromagnetism

What Is Potential Difference (Voltage)?

Potential difference is the energy transferred per coulomb of charge between two points, defined by V = W/Q and measured in volts. This guide covers the formula, worked examples, three common myths, and why a bird on a power line is safe.

14 min read

Electromagnetism

What Is Electric Current?

Electric current is the rate of flow of electric charge, given by I = Q/t and measured in amperes. Here is what it really is, why electrons drift so slowly, and worked examples.

13 min read

Waves & Optics

What Is Polarization of Light?

Polarization of light is the direction a light wave's electric field vibrates in. Learn Malus's law (I = I0cos²θ), Brewster's angle, real-world examples and worked problems.

14 min read

$What Is Diffraction in Physics?$

Waves & Optics

What Is Diffraction in Physics?

Diffraction is the bending and spreading of waves through gaps and around edges. Learn the grating formula d sin θ = nλ with six real-world examples, worked problems and an interactive lab.

15 min read

Waves & Optics

Dispersion of Light and Prisms

Dispersion of light is why a glass prism splits white light into a rainbow. Learn why violet bends more than red, the key formulas, and 7 real-world examples.

15 min read

Thermodynamics

Boyle’s Law: Pressure, Volume and the P1V1 = P2V2 Rule

Boyle's Law states that the absolute pressure of a fixed mass of gas is inversely proportional to its volume at constant temperature, so P₁V₁ = P₂V₂. This guide covers the formula, the graph, five real-world examples, four common traps and seven worked problems.

17 min read

Classical Mechanics

Charles’s Law Explained

Charles's law states that the volume of a fixed mass of gas at constant pressure is directly proportional to its absolute temperature. Learn the V1/T1 = V2/T2 formula, why kelvin is non-negotiable, and work through eight problems from balloons to hot-air lift.

16 min read

Waves & Optics

Concave vs Convex Mirror

A concave mirror curves inward and converges light to a real focus; a convex mirror bulges outward and diverges it from a virtual focus behind the glass. Ray diagrams, the mirror formula, seven worked problems and the reason your wing mirror lies about distance.

18 min read

Thermodynamics

What Is the Ideal Gas Law (PV = nRT)?

The ideal gas law, PV = nRT, links a gas's pressure, volume, amount and absolute temperature in a single equation that works for every gas. This guide covers the formula, the molecular reason behind it, eight worked problems, and the four errors that cost the most marks.

18 min read

Classical Mechanics

Mechanical Advantage and Simple Machines

Mechanical advantage is the load force divided by the effort force — the number of times a machine multiplies what you push with. This guide covers the formula, ideal vs actual MA, all six simple machines, and eight worked problems.

17 min read

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