I don't know if it is because of my latest question on main or because of all good help I am getting. can someone tell me if there is a reason I get more faster as I obtain more?
You've been on this site for a sum total of two weeks. That is nowhere near enough data to say anything conclusive.
In particular, the only backing in your reputation tab for the observation that you report is the linear progression from January 27 through January 29:
Note that this growth trend is already on some shaky ground.
The simplest explanation that you're getting more reputation over the last couple of days is that your fourth question is better than the previous three.
Seriously, though: take it easy. Read as many questions and answers as you can, use them to write the best questions and answers as you can, take your time when writing posts, and worry about the details of site mechanics like reputation later.
Emilio Pisanty's answer covers your specific case pretty well, but it's worth addressing the question
"[Is there] a reason I get more faster as I obtain more?"
I think it's pretty trivial/general and there's no real need to ask that kind of thing on meta. Obviously, if you participate at almost anything for some time, you'll get the hang of it and start doing it better. The rep gained is an indication that you've put together a well-received question (this one), and while that may simply be coincidence, it may be because you have a better idea of how to ask. That being said, there is some speculation (cf. this Meta SE post and links therein) that people are less reluctant to upvote a post by a high-rep user, but in your case (70 rep), I doubt that it's a significant factor.
Still, you could relax with the meta posts... questions like this one, this, this, and this are the kind of thing which you could/would answer yourself if you hang around the site observing interactions and questions for a couple of weeks and exploring the help center a bit. Posting everything on meta is really not necessary, in fact at a certain stage it becomes harmful because it fills up the front page, hiding important stuff and consuming peoples' time. For instance, this week saw a lot of complaints and poorly thought out feature-suggestions (I make that claim since they were heavily downvoted), a few of which were yours, and some stuff which I feel could have spent some time on top (this and this) got submerged. Furthermore, if you have such a large number of meta posts, people will start wondering if you're relying on the 'meta effect' (whereby you draw attention to your posts by 'advertising' them on meta) to get votes, and it will become difficult for people to assume good faith. SE has a complex privilege and moderation system, which can have a big impact on usage patterns, so it's understandable that you're curious. But please, observe, speculate, and research before asking everything on meta.
On a side note, questions which get you rep are, more often than not, not good questions. A key feature of most high-scoring questions is accessibility, not quality, due to the HNQ (Hot Network Question) effect. So perhaps if you spend some months/years around and start asking questions which are of interest primarily to people who specifically study physics, the upvotes will slow down.
I would like to add another potential cause: Occasionally when you post questions or answers, reputation gains trickle in every once in a while for a longer amount of time, so it's the amount of good questions and answers that boost the speed of your reputation gains and not the reputation itself.
I believe that in your case Emilio's answer is the accurate one, but if you notice an increased rep gain in the future, this might be another possibility.