Any player with less than 10 wins will get a considerable amount of ELO gained, or lost. This usually is ~40, and will eventually diminish to your normal ELO gains/losses you see ~11.
As for duo queuing, if you chose to queue with a large ELO gap, you need to keep a few things in mind:
- You're more likely to be last pick.
Because of the difference in ELO, it's harder to find a suitable team of which you two fit evenly into. The result is the lower player is typically last pick, with the remaining team mates chosen to make up for the gap between your ELOs.
- Your ELO gains/losses are affected
A player whom wins a ranked match and is higher ELO than his opponents will naturally receive less ELO after a win. As you would imagine, that player would also lose more elo upon receiving a loss.
The same can be said for a player that finds them self on the low end of the match. They would receive more for a win, and less for a loss.
I highly recommend reading this entire article: League of Legends ELO Breakdown