can i use ip no. as dns server 1 & 2 for my website ???? i bought the domain form yahoo?

Answer 1

If you are attempting to host this yourself you will also need to register dns servers. You can register those with the domain registrar for your domain but you have to have TWO IP's one for each dns server.

You can not use IP number for a dns server, you have to have the registrar enter a record which would connect each DNS name to an IP
dns1.yourdomain.com = youripnumber
dns2.yourdomain.com = your other ipnumber

If you do not have two IP's you may want to have an outside DNS service for your domain.