I am running a PPC campaign with 7 ad groups.In these ad groups some are working fine, but for few ad groups only impressions are happing, but no clicks are there. The quality scores of the keywords for the particular ad groups are either ok or great.But I am running only a single ad for all the ad groups. The Max CPC is also high. Can you please tell me what should be the reason for no clicks and conversions?
i'd start by adjusting your ad copy for the adgroups that aren't getting clicks...if you're running one ad across 7 different adgroups, there has to be an adgroup or two where the ad isn't quite as relevant.
try playing around with the ads in the poorly-performing groups.