Indeed. Undesirable loading effects can occur in countless applications, from DC to Daylight. For DC circuits, it's important to have a very high resistance voltmeter...this is why the VTVM was invented (vacuum tube voltemeter)...back in the dark agesLoading has to do with the fact that the load (device to be driven) is effectively connected in parallel with the rest of output circuit which is attempting maintain the output voltage. But because of the parallel connection, the overall opposition to current decreases thus requiring more current to flow from the output - current that the output may or may not be able to provide. If it does not provide, the output's voltage will fall.
by Duane Benson
by Aaron Carman
by Duane Benson
by Jake Hertz