Got some help from other experts..
In order to get the board name for the Raspberry Pi, we have to first get the Revision number from /etc/cpuinfo and then
map it with the table given in the following wiki..
http://elinux.org/RPi_HardwareHistory
So on my Raspberry board
~# cat /proc/cpuinfo
processor : 0
model name : ARMv6-compatible processor rev 7 (v6l)
Features : swp half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xb76
CPU revision : 7
Hardware : BCM2708
Revision : 000e
So checking for '000e' in the table, shows me that my board is B and Pcb revision is 2.0.
Thanks all for your inputs.