Wriggle and squirm all you like. Just read the article and related links to conventional clutch and automatic transmission [which have wet multiplate clutches within]. It will help you a lot. As a direct answer to your question, power is converted to torque at a lower speed and waste heat. In effect it slips. This is not the case with a conventional clutch which is just an on/off switch. You should have known this even if your engineering experience was limited to school metalwork :o]
Huw
Huw