Hi there pramodts,
That is really unpleasant.
Unfortunately, it is possible that the power surge damaged the device .
How does the drive show up under Disk Management?
I guess you can test the drive with WD's Data Lifeguard Diagnostic tool:
http://products.wdc.com/support/kb.ashx?id=QSr9Nn
Also, trying something simple as just using a different USB cable will not hurt.
In case the drive is not recognized by the DLG tool, then I guess there is something wrong with the enclosure or the HDD itself.
Let me know how this goes,
D_Know_WD