After struggling for four hours with this , I finally found a solution.I hope this saves someone.

Now if you have just installed Ubuntu and are not able to see your available wireless connections the following helped me;

Connect to the network through an Ethernet cable. You can actually USB tether to your phone.
Then run the following commands. 
            `sudo apt-get update`
            `sudo apt-get install bcmwl-kernel-source`                   
Disconnect your Ethernet and the wireless connections should be visible now.