Yes. Because the College Board is committed to providing access to the AP Exams to homeschooled students and students whose schools do not offer AP it does not require students to take an AP course prior to taking an AP Exam.
The College Board urges students to study the kinds of skills and subjects outlined in the Course Description for each subject, because they represent the basis for the AP Examination. The best way to do so is in a year-long AP course in which the students and teachers focus on AP-level work. Some students, however, have taken strong courses and/or have studied in depth on their own. Such students may be able to perform quite well on the AP Exam.
If you have a documented disability, you may be eligible for accommodations on AP Exams. To find out more, visit services for students with disabilities or contact your school's AP Coordinator.
If you take an examination as a senior, colleges will not receive your grade before July–probably well after you have been admitted. If you choose to report AP grades obtained before your senior year, you will primarily be telling the colleges that you undertook a difficult course and that you are serious about your studies. Overall, approximately two-thirds of all AP test takers receive AP grades of at least 3. This grade is regarded as an indicator of an ability to do successful work at most colleges.
You can take an AP Exam each time it is offered (AP Exams are offered once a year in May). Your grade report will include your grades for all the AP Exams you have taken, including yearly "repeats" of the same subject exam.
Most of the exams take two to three hours to complete. For subjects that correspond to half-year college courses, the exam is closer to two hours in length. Your AP Coordinator should notify you of the exact exam starting time. You can also take a look at the current exam schedules for days and dates.
The answer to the first question is "yes," but not as much as you might think. Your score on the multiple-choice section is based on the number of questions you answer correctly minus a fraction of the number of questions you answer incorrectly. (One-fourth of a point is subtracted for a wrong answer in questions with five answer choices, and one-third of a point in questions with four answer choices.)
The answer to the second question is a conditional "yes." Random guessing is unlikely to raise or lower your grade if you are unsure about the answer to a question, because of the formula (described above) used to deduct points for wrong answers. However, if you have SOME knowledge of the question, and can eliminate one or more answer choices, informed guessing from among the remaining choices is usually to your advantage.
If you are an AP Scholar Award recipient, you and your school will be notified in the fall after the May administration. After that time, grade transcripts that you request to be sent to colleges will include the scholar designation.