IGCSE 0625 / Section 4.2.1 / Core

Two charges, one rule.

Rub a balloon on your hair and it sticks to the wall and lifts your hair toward it. Nothing was added but a brisk rub, yet the balloon now pushes and pulls on things across a gap. That is electric charge at work.

The key idea

There are two types of charge, positive and negative. Like charges repel and unlike charges attract. Rubbing two insulators together transfers electrons: the one that gains electrons becomes negative, the one that loses them becomes positive.

Definition · learn the exact words

There are two kinds of electric charge, positive and negative. Like charges repel and unlike charges attract. An insulator can be charged by friction, which transfers electrons.

like charges repel · unlike charges attract

The object that gains electrons becomes negative; the one that loses electrons becomes positive.

Section 01

Charge it by rubbing.

Transfer electrons between objects and watch the charges attract or repel.

Stage 1 · Learn

Check charge

Four quick checks. Each correct answer earns XP and lights this skill on your star map.

Quick check+10 XP

Two objects carry the same sign of charge. They will...

Quick check+10 XP

A polythene rod rubbed with a cloth gains electrons. The rod becomes...

Quick check+10 XP

Charging an insulator by friction transfers...

Quick check+10 XP

A positive charge and a negative charge will...

Section 02

It is the electrons that move.

Charging by friction shifts electrons from one surface to the other.

Examiner trap

It is electrons that move, not positive charge. The object that gains electrons becomes negatively charged, and the one that loses electrons is left positive.

Stage 2 · Exam

Exam-style questions

Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.

Finish the four checks above to unlock the exam questions
Exam style+20 XP

Two light balls hang on threads and swing apart from each other. This shows they carry...

Exam style+20 XP

A cloth rubbed on a rod loses electrons to the rod. The cloth is left...

Exam style+20 XP

When a plastic comb is charged by rubbing, the particles that are transferred are...

Skill unlocked

Charge, mastered.

Electric charge is mapped. Keep the chain going.

-Rank -Level -Score -Topics
Go deeper · practice
Six original Cambridge-style questions
Positive and negative charge, the force rules, and charging by friction through electron transfer. Attempt each, then reveal the worked solution.
Stage 3 · master the unit
Electricity and magnetism challenge
Mixed questions across the whole unit, each one worth XP. Start this only when you feel confident across every topic in the unit, not just charge.
Start the unit challenge →