Starting with the 10XX series. It seems Nvidia no longer has Analog video outputs. Older cards switched from 2 down to 1 and now we have none.
As said above you will need an Active adapter(most, but not all require power from a USB port or similar).
You can see this change by the fact that they now only have DVI-D ports(Digital only can be converted to HDMI with a passive adapter.) instead of DVI-I ports(can be converted to VGA or HDMI with a passive adapter.).
If you look at the following link you will see the different between the different DVI ports.
https://en.wikipedia.org/wiki/Digital_Visual_Interface
This was an image for another thread, but you can see DVI-I on the motherboard(red) and top video card port and DVI-D on the video card(blue). Note the missing pins around the flat contact on the side of the plug.
While I have not seen it on Nvidia cards, I did find some AMD cards that had DVI-I Ports connected as DVI-D only. This allowed passive adapters to fit, but not function.