2 website different tld with same content can they both rank?

I've been ranking on two sites for the past few months and i notice when one ranks well for a keyword say "test" the other site will drop down the list for the same keyword ranking for "test"

so my question is when i have multiple sites with different .tlds with the same content how dose google treat it?

1. google will penalize both and not rank it?

2. google will rank both just the same?

3. google will rank one and ignore the other?

this is assume they are competing for the same keyword.

 

google will rank both of you site, and google will rank higher you site with quality backlink

 

What's a good way to generate backlinks?

 

In the old times Yes now with panda and the content importance No ...