There are many websites with exam questions. Some offer questions released by the USPTO. Others offer some sample questions written by the bar preparation services. Be CAREFUL! Some offer Patent Bar Registration exams administered between 1997 and 2003. Note that these questions should not be considered accurate or applicable to current laws, regulations, or policies. No official USPTO Patent Bar Exam has been released after 2003. The current examination covers the subject matter designated by the USPTO in the source materials. Applicants should regularly check the source materials to verify the subject matter that may be tested, as the materials may be revised from time to time, including during their examination window.
This is one are where you need to seriously assess each commercial bar prep provider. Most offer the value added of questions written by their experts that they consider to be good preparation for the exam. Look at pass rates by each provider. See if they discuss the credentials of the drafters of their proprietary questions.
Patent Education Series (Volume I sample)