IGCSE 0625 / Section 4.2.2 / Core

Charge on the move.

Flick a switch and a lamp lights at once. What flows round the wires is electric charge, and how much passes each second is the current. Measuring it just means putting a meter in the path.

The key idea

Electric current is the flow of electric charge, measured in amperes by an ammeter connected in series. Conventional current is taken from positive to negative, while electrons drift the other way. Direct current flows one way; alternating current repeatedly reverses.

Definition · learn the exact words

Electric current is the flow of electric charge, measured in amperes (A) by an ammeter connected in series. Conventional current flows from the positive terminal to the negative terminal.

ammeter in series · unit: ampere (A)

Direct current (d.c.) flows in one direction; alternating current (a.c.) repeatedly reverses direction.

Section 01

Put the meter in the path.

Connect the ammeter in series so the whole current flows through it.

Stage 1 · Learn

Check current

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

Quick check+10 XP

Electric current is measured with...

Quick check+10 XP

An ammeter is connected in...

Quick check+10 XP

Conventional current flows from...

Quick check+10 XP

The unit of electric current is the...

Section 02

Direction and type.

Conventional current and electron flow run opposite ways, and current can be steady or alternating.

Examiner trap

An ammeter is connected in series, not parallel, so the whole current passes through it. Conventional current is taken from positive to negative, even though the electrons actually drift the opposite way.

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

In a direct current, the charge...

Exam style+20 XP

To measure the current through a lamp, an ammeter should be connected...

Exam style+20 XP

In a metal wire carrying conventional current from left to right, the electrons actually move...

Skill unlocked

Current, mastered.

Electric current is mapped. Keep the chain going.

-Rank -Level -Score -Topics
Go deeper · practice
Six original Cambridge-style questions
Current as the flow of charge, the ammeter in series, conventional current direction, and a.c. versus d.c. 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 current.
Start the unit challenge →