About URL Structure ?

We currently have the following URL structure on our site ​

"http://cbse.meritnation.com/cbse-math/real-numbers/9/128/tutorials.html" ​

We plan to move to the structure which is as follows:​

"http://www.meritnation.com/cbse-math/real-numbers/9/128/tutorials.html"​

Our understanding is that new structure will improves SEO on the site and also dramatically affects the SERP of our pages. ​

My question to the community is:

1. Are these correct assumptions
2. Will there be a large impact on traffic from search engines in short run
3. How do we minimize the impact on SEO - should we use 301 / 302 redirects on the old URLs or are there any other better options
4. How long will it take for us to return to the normal traffic from SEO

 

Yes all these are correct. Actually both the above patterns are correct and seo friendly.