extra file size

Hi, I recently formatted my PC and lost my OBS settings. Before reset, a 1.5hr video would take about 300MB. But now after reinstalling OBS (With default settings) a 1.5 hr video takes about 1.6GB of space. The recordings are of my online classes. Can someone suggest me some settings that would...

I face problems recording in full screen mode. When I record video in full screen mode i.e Youtube, VLC media Player, I get a larger file size. If I record without full screen, I get 3 mega byte video recording per minute. But if I record in full screen, I get 8-9 mega byte video recording per...