Are there some ASVAB practice exams that are more legitimate than others?

Question

Additionally, how difficult is the exam? I am currently a college junior majoring in physics with a 3.97 GPA.

Answer 1

Study for the ASVAB? If you’re in college why would you take the ASVAB? It’s to help determine what vocation you might have an aptitude for. It’s more for trades than academics.

Answer 2

Do you know what the ASVAB is?  It's a test given to determine military enlistment qualifications.  It's usually high school students who take it.  In any case, I do believe you can find sample/practice tests online.  Someone in your situation should not find it particularly difficult.