is there a correlation between working memory and intelligence and has there been any studies on the topic plz

Answer 1

Yes of course - working memory builds upon experience therefore increases knowledge and intelligence, as it has done with your awareness of this fact.

Answer 2

You should be able to find plenty of info on this topic .... a great deal of research has been done to understand the relationship between the two. To that end many tests have been done involving sleep deprivation which expands the working memory areas and which (as the theory goes) after the REM cycle, can boost ones IQ once the region is no longer needed for working memory.