TDK has demonstrated a fast optical sensor based on a magnetic tunnelling junction - a spin photo detector. he device is ...

A magnetic field is invisible, but it can be detected using a magnetic compass. A compass contains a small bar magnet on a pivot so that it can rotate. The compass needle points in the direction ...

The needle is being affected by the Earth’s magnetic field. One end points towards magnetic north and the other end points south. You can use a compass to check which direction each end is facing.

The metal detector part of the project is fairly ... where short pulses are fired through a coil to generate a magnetic field. Once the pulse ends, the coil is used to detect the decaying field ...

But not everyone is convinced. Electricity can be generated from the energy of Earth rotating through its own magnetic field — according to a provocative claim put forward by physicists today.