Electric Measurements

Common electric measurements are usually made with digital multimeters, but the examination of moving coil meters contains a number of good examples of electric and magnetic interactions.

The design of a voltmeter, ammeter or ohmmeter begins with a current-sensitive element. Though most modern meters have solid state digital readouts, the physics is more readily demonstrated with a moving coil current detector called a galvanometer. Since the modifications of the current sensor are compact, it is practical to have all three functions in a single instrument with multiple ranges of sensitivity. Schematically, a single range "multimeter" might be designed as illustrated.

Voltmeter designAmmeter designOhmmeter design

DC Circuits
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