BBC5 年
What are magnetic fields? - OCR 21st Century
A magnetic field is invisible, but it can be detected using a magnetic compass. A compass contains a small bar magnet ... needle direction each time join the points to show the field lines The ...
BBC4 年
Detecting and drawing magnetic fields
A magnetic field is invisible, but it can be detected using a magnetic compass. A compass contains a small bar magnet ... needle direction each time join the points to show the field lines The ...