There isn't a standard answer because it's going to depend on how much data your user needs in order to fulfill their task. They might only need a "top 10" glance, or in other cases, 200 rows might have valuable information.
Analytics is your friend. If you have access to an analytics platform (even user session playback), you can see how many times users are changing the number of results they wish to see, and how many pages they're looking at in the pager (you might need to tag the components in order to start collecting data).
Watch this data for 2 weeks (unless you have very little traffic, in which case, you'll need longer), then approximate the size of the dataset that they're consuming; that can give you an idea of a good default.