The Armed Services Vocational Aptitude Battery, or ASVAB, is a series of tests used by the military to determine a solider's strengths, weaknesses and abilities. Performance on the ASVAB helps determine the test-taker's career placement and future leadership potential. The higher you score on the ASVAB, the better your chances are to land your preferred job placement within a branch of service.

The ASVAB and Its Subtests

The ASVAB is a series of 8 to 10 subtests; the number you take depends on which test you are given. According to the ASVAB site, there is no standalone science test, but rather a series of subtests that, when scored together, comprise a recruit's science score. The subtests that are part of the science score include: general science, electronics information, auto/shop information and mechanical comprehension. The general science subtest consists of 25 multiple choice questions with an 11 minute time limit. The electronics information subtest has 20 multiple choice questions with a 9 minute time limit. The auto and shop information subtest has 25 questions with an 11 minute time limit. The mechanical comprehension subtest has 25 questions with a 19 minute time limit.

The General Science Subtest Questions

According to the ASVAB testing site, the general science portion of the ASVAB covers physical science and biology. Questions cover the body and its organ systems, as well as the cell and its structures, the atoms, compounds, the periodic table, chemical reactions, the earth's structure, the oceans and the earth's atmosphere. In general, according to TestGuide.com, the science questions in this section either require completing the sentence (For example: A Celsius temperature of 100 degrees is equivalent to a Farenheit temperature of _.) or answering the question (For example: Which of the following is a positively charged subatomic particle?). Many of the questions in this section rely on vocabulary knowledge, so you should develop a good working general science vocabulary.

Mechanical Comprehension Questions

The mechanical comprehension subtest covers simple machines, gears, measuring work, friction, power, force and pressure and machine elements. The mechanical comprehension subtest differs from the general science subtest, however. According to the Coast Guard Training Center, the mechanical comprehension subtest uses drawings or figures for many of the questions. An example of a question in mechanical comprehension that requires an illustration is an incline plane paired with a question asking whether or not the drawing is of a simple machine. Some, however, do not require an illustration, such as: Which of the following would happen when a mass of air contracts? Some questions also require prior knowledge and science application, for example: Which of the following would feel the hottest at one end if the other end were placed over a fire? All of the questions are multiple choice.

Electronics, Auto and Shop Information Questions

The electronics information portion of the ASVAB covers circuits, Ohm's Law, measuring power, electromechanical induction, household wiring, DC and AC current, and basic electronic theory.The auto and shop information subtest covers auto and shop technology, processes, practices and procedures. The electronics information subtest, according to TestGuide, is vocabulary intensive, with questions much like the General Science subtest. Recruits answer questions (For example: An ammeter measures what?) or fill in blanks in sentences (For example: Neutral wire is colored___). The auto and shop information subtest is fill-in-the-blank and requires some prior knowledge (For example: The best way to sand the end grain of wood is_.).