Apparently, Evince – the default PDF viewer in Fedora (and probably with most of the Gnome based distros) cannot zoom a document more than 400%. In my case, it would not even zoom more than 383% which makes it very difficult to view the schematics with tiny components and lines. By googling a bit, I came to a bug report for the same issue and the bug is still open.
So I tried xpdf, which still has a century old UI. Ultimately found a new pdf viewer : Qpdfview which has an additional feature of opening multiple PDFs in tabs. Yay!