Q: my ipad restarts from the day i updated IOS 8.0.2

Hello alokgupta,

I know the article is for iPhone, but it does work for iPad as well when dealing with power and restart issues. Check out the Power/Battery section to get it working and not constantly restarting on you. 

iPhone: Hardware troubleshooting

http://support.apple.com/kb/TS2802

Regards,

-Norm G.