Where principal component analysis can potentially be used ? some examples with some explanation would be great
Searching on ScienceDirect with a keyword Principal Component Analysis might give you a nice overview of the range of disciplines where PCA is used, as well as the type of problems in which PCA succeeds.
PCA, in general, applies to high-dimensional data sets (meaning ones that are described by many parameters) but which contain lower-dimensional structures (meaning they can be almost as well described by a lower number of "substitute" parameters, called principal components). These data sets might come from various fields: neuroscience, climate science, combustion, to name a few.