Electromagnetism
2 guided lessons · 18 checks · 6. Magnetism and Electromagnetism → Magnetism and Electromagnetism
Guided lessons for this note
Which concept don't you understand yet?
We'll explain it simply and check your understanding. Pick any lesson — any order works.
0 of 18 checks correct so far
Lesson 1 of 2
Current as a source of magnetic field
Switch on a current and the space around the wire changes: a current flowing in a conductor sets up a magnetic field in the space around it. The field's map is a set of circles centred on the wire, their direction set by the current — reverse the current and every circle runs the other way.
What you know already
An electric current is a magnetic-field machine: switch it on and circles of field wrap around the conductor, switch it off and they vanish. This note draws the circular pattern around a straight wire, fixes its direction with the grip rule, and names the two levers — current size and distance — that set its strength.
Key points of understanding
- A current flowing in a conductor sets up a magnetic field in the space around it.
- The field lines around a straight wire are circles centred on the wire.
- The field direction follows the current, given by the right-hand grip rule.
- Reversing the current reverses the direction of the field circles.
- Switching the current off collapses the field — the field exists only while current flows.
Diagram showing the magnetic field around a current-carrying wire
The right-hand thumb rule shows the direction of current flow through a wire and the direction of the magnetic field around the wire
Side and top view of the current flowing through a wire and the magnetic field produced
Choose a confidence level to continue.
Prefer to read it all at once? Show the full lesson as a page
1.Current as a source of magnetic field
Switch on a current and the space around the wire changes: a current flowing in a conductor sets up a magnetic field in the space around it. The field's map is a set of circles centred on the wire, their direction set by the current — reverse the current and every circle runs the other way.
Diagram showing the magnetic field around a current-carrying wire
The right-hand thumb rule shows the direction of current flow through a wire and the direction of the magnetic field around the wire
Guided content from the SME authoring corpus — note rn_vpyY8DrdsZGwBjBX, pinned at 6312d659ec0d · promoted SyllabAI/syllabai-resources b3caaaa90c5e
