You will be told if the import was successful. If so, the question has now been added to the course question bank:
Depending on the question type, there can be a great many configuration options you need to set in order to create questions to add to the question bank. Hot Potatoes is a great tool for creating questions quickly and efficiently, and we've just seen how easy it is to import Hot Potatoes questions into Moodle. Think about using Hot Potatoes if you've got a lot of questions you need to convert to Moodle.