SOLUTION

The D’Arsonval movement, also known as a moving coil galvanometer, is the mechanism commonly used in analog meters with a pointer moving across a scale.

• It works on the principle of motor action: current through a coil in a magnetic field causes the coil to rotate, moving a pointer across a scale.
• The amount of rotation is proportional to the current.
• Springs restrain the coil, ensuring the pointer deflects proportionally to the current and returns to zero when the current stops.
• It can measure DC current or AC current rectified to DC.