This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Mahendran A, please check your private messages. You can see them by clicking My Private Messages.
To answer your question: No, you cannot instantiate an abstract class. An abstract class is a class that is not yet "finished" - it contains methods without an implementation. A non-abstract subclass is supposed to implement those methods.