Topic Cluster

Electromagnetism

Electric charge, fields, current and magnetism. From Coulomb’s and Ohm’s laws to electromagnetic induction and circuits — how charges and fields work.

Electromagnetism

Faraday’s Law Formula: Calculating Induced EMF

The Faraday's law formula, ε = -N(ΔΦ/Δt), gives the EMF induced in a coil from the rate at which magnetic flux through it changes. This guide covers every symbol and unit, the four-step calculation method, all four rearrangements, and seven worked examples.

14 min read

Electromagnetism

AC vs DC Current: What’s the Difference?

AC reverses direction 100 times a second; DC flows steadily one way. Here are the 7 key differences, the RMS formula behind the 230 V on your plug, and why the grid runs on AC while everything plugged into it runs on DC.

18 min read

Electromagnetism

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

Electromagnetism

Electromagnetic Induction and Faraday’s Law

Electromagnetic induction generates a voltage when the magnetic flux through a coil changes. This guide covers Faraday's law, Lenz's law, the EMF formula, worked examples and the everyday technology it powers.

11 min read

Electromagnetism

What Is an Electric Field?

A clear, complete guide to the electric field: what it is, the two key formulas (E = F/q and E = kQ/r²), how to read field lines, five real-world examples and worked problems.

15 min read

Electromagnetism

What Is a Magnetic Field?

A clear guide to the magnetic field: what it is, the F = qvB formula and its units, how fields are produced, seven real-world examples, common myths, worked problems and FAQs.

16 min read

Electromagnetism

What Is Static Electricity?

Static electricity is the build-up of electric charge on a surface when materials gain or lose electrons. Here's how it works, why you get shocked, and five everyday examples — from clingy clothes to lightning.

14 min read

Electromagnetism

Series and Parallel Circuits Explained

A clear guide to series and parallel circuits — how current, voltage and resistance behave in each, with original diagrams, formulas and eight worked examples.

12 min read

Electromagnetism

What Is Ohm’s Law?

Ohm's law links voltage, current and resistance through V = IR. Master all three formulas with worked examples, an interactive circuit lab and the misconceptions that trip students up.

15 min read

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