Lens Contacts (electrical)

I have some old lenses, Sigma mini wideII (macro) with A position and an old Tamron 70-210 Zoom (model 103A). I know the manual says that lenses with position A can be used and that there is a setting to allow aperture ring use but, if I attached say the zoom and didnt set aperture ring use would the mount short the electrical contacts on the camera body and cause damage?
Sorry to appear dumb, but I dont want to damage the camera by doing something stupid.
I have however just bought a sigma 55 - 200 lens. Anybody had any experience with these? My first impression is that it seems ok.

No, it wouldn't be a problem. If you mount a lens with no A setting and don't activate the use of the aperture ring the lens will operate at full aperture all the time.

If there is an A setting just use that and the lens will behave like any of the current range with no aperture ring.

I use a telescope with a metal K mount that has no contacts on it at all, and the camera works fine.

Edit - in totally manual mode only.

No it wouldn't damage the camera or the lens.
The camera is just unable to read the aperture value when using the apeture ring so if you don't enable that it would simply refuse to make a photo since it doesn't have an aperture value.

They have put this option on for the newer lenses so as the DA, they don't have an apeture ring so when the camera doesn't get the info it means the lens is not correctly mounted.

edit: typo, it was late

If it's the AF version it's a good lens.

I have one and use it regularly, it's handy to have in the bag on city breaks as a back up to the standard lens.

If it's a manual lens, sorry can't help.

Mant thanks for all your advice once again. The 55 - 200 Sigma is the AF version. Glad to hear you find it useful Hardgravity.