What are some great ideas to get on a long conversation(over phone) with a girl whom i love most ?

You might be thinking about this the wrong way. I say this because when you really like someone and things are right, conversation comes natural. My high school sweetheart is a perfect example. We were together for about 5 years. Before we dated, we were friends for about 6 months. We met through mutual friends. We had very compatible intellects, similar interests, and both very curious and open minded. We would spend hours on the phone. One random comment would lead us into multiple tangents until our ears were burning hot from the cordless phone. However, maybe you are shy? So just show genuine interest. Ask her to talk about her day, discuss things you are passionate about. Tell her a funny story that happened to you that day.

First and most important: actively listen to what she is saying and be genuinely interested in what she has to say. I cannot stress that enough, though it sounds like you already have that down. If there's any advice I can give you, it's to become really good at telling your own story. Not everyone has that spontaneity or levity to keep jumping from tangent to tangent to tangent, so always be prepared to share something about yourself or relate a part of your story to a part of the ongoing conversation. Also, brief pauses are not terrible. Keeping yourself well composed is better than unending rambling. Hope this helps!

It appears as if we've got a serious case of the Oneitis on our hands. If you already have her number, man up (maybe have a lil' scotch beforehand to get all loosy-goosy) and give that girl a shout. Don't force the convo, it'll go as long as it'll go. There is nothing more awkward than when one person in a convo is forcing it to go in one direction. But straight up homie, meet more girls. You shouldn't be feeling this way about a girl unless you've been dating for a while.

The way to talk to a woman for a long time is to ask lots of questions about whatever topic she wants to talk about.   I will warn you it is not easy, because women tend to be intuitive and will catch on easily, even over the phone, that you are faking it. You have to practice to learn to be unbelievably interested in whatever mindless tripe she is talking about.

If you are running out of ideas of what to talk about, it's not love.  I would recommend you not call as much so you have more things to talk about when you do call.