I have small number of visitor and my bandwidth is 1000 MB and i tried to know the reason that my site exceeded the bandwidth but I couldn't figure it out so can help me ?
There are various tools in cPanel which can be used to monitor the bandwidth used, login to cPanel->under log section-> find the tools like
Latest Visitors, Bandwidth, Webalizer, Webalizer FTP, Raw Access Logs, Analog Stats, Error Log, AWStats, Resource Usage
The tools marked in bold are my favorite.