If an extension device contains active circuitry (typically a simple impedance converter with a low-noise FET) then it's active, of course.
But if the FET is in the housing along with the capsule, then the capsule is what's active. A good example of that arrangement would be Neumann's KM 100-series microphones. The capsule heads for that series are the AK 20, AK 30, etc.--the "A" stands for "active" because the capsule heads themselves contain the impedance converter stage (see attached photo; the bottom half of the capsule head is an impedance converter "barrel" that is common to all this series of capsules).
In some microphones that have remote capsule capability, there's no active circuitry either before or within the capsule extension devices--though of course those designs can be vulnerable to a loss of signal quality both due to stray capacitance and RFI. Such microphones don't always hold up well at concerts where there can be dozens of GHz-range transmitters close by in people's pockets, but they're a lot cheaper to manufacture.
Does that make sense? If a capsule extension device (cable, gooseneck, whatever) has active circuitry in it, it's active; if not, then it's just a capsule extension cable, or a capsule extension "whatever."
My apologies to the original poster for temporarily hijacking the thread; let's return to his original question now, OK?
--best regards