Ph.D. qualifying exams vary significantly by department, often reflecting specific research areas. The University of Cincinnati offers a repository of past physics qualifying exams that can be useful for preparation. It's recommended to contact the department directly for old qualifiers, as they provide the most relevant study material. Additionally, books like "Problems and Solutions in Classical Mechanics" are valuable resources for practice, despite their high cost and occasional errors in solutions. Ultimately, familiarizing oneself with the specific content and style of the department's exams is crucial for effective preparation.