A:
No. The Thunderbolt connector on your iMac will likely allow you to use it to connect another Mac to it, but without a different adapter it will not take an HDMI signal through this adapter. This adapter is to convert a Thunderbolt signal to HDMI, not the other way around. See these articles for more info:
https://discussions.apple.com/thread/3036832?start=0&tstart=0
http://bigmacky.wordpress.com/2009/10/25/connecting-a-playstation-3-to-your-imac/