Why does it only show voltage when generating a weak current?

Question

Electronics

Guys, such a question, I connected the multimeter to the coil, I run it with a magnet, it shows a voltage from 0.1 to 1.5 mV, and when I try to measure the current strength, it doesn’t show anything at all, because some current passes there at that moment or the multimeter does not have time to measure it tiny madness?

Answer 1

It's all about the fundamental difference between a voltmeter and an ammeter. A voltmeter is a device that has a very high input resistance (ideally infinitely large), so it consumes very little current from the measured circuit (ideally close to 0). The ammeter must be included in the break of the circuit being measured, so the opposite is required of it - its internal resistance must be very small (ideally close to 0), otherwise it will affect this circuit and introduce an error into the measurement by its presence.
A multimeter can be both. In voltmeter mode, the digital multimeter has an input resistance of 1 megohm, and in ammeter mode (at 10 amperes) - 0.01 ohm.

or the multimeter does not have time to measure this tiny madness?

Yes it is. The digital camera makes only 2 ... 3 measurements per second, this is too slow, therefore, to wave the magnet around the coil, you must use not a digital device, but a pointer, and even better, an oscilloscope.