ASVAB ASVAB Certifications ASVAB-SECTION-3 Questions & Answers

• Question 111:

  Pliers are an example of a ___________.

  

  A. first-class lever

  B. second-class lever

  C. third-class lever

  D. fourth-class lever

  Correct Answer: A

  Pliers are an example of a first-class lever because the fulcrum is positioned between the effort (where your hand grips the pliers) and the load (the object that is being held or squeezed by the pliers).

• Question 112:

  The lift caused by an aircraft's wings is primarily due to ___________.

  

  A. a decrease in pressure on the upper side of the wing (A)

  B. a decrease in pressure on the bottom side of the wing B

  C. a vacuum created under the wing at point B

  D. an increase in pressure on the upper side of the wing (A)

  Correct Answer: A

  When oncoming air meets the leading edge of the airfoil (wing), some of it goes over the top of the airfoil and some of it flows underneath. The air flowing over the top of the wing has to go further than the air underneath, because it must join together again with the air that flowed under the wing at the far (back) side of the wing ?physical laws act together to prevent or minimize vacuums in most cases.

• Question 113:

  Heat is a form of ___________.

  A. calories

  B. energy

  C. beneficence

  D. motion

  Correct Answer: B

  Heat is a form of energy - Calories measure heat, beneficence is an attitude or emotion, and motion is something that can cause heat.

• Question 114:

  

  The figure above represents a water tank. Which of the following statements is not true?

  A. If Valves 1 and 2 are open and Valves 3, 4, and 5 are closed, the tank will eventually overflow.

  B. If all valves are open, the water remains at a constant level as long as the rate of intake is equal to the rate of discharge.

  C. Water in the tank will rise if Valves 1 and 2 are open and Valves 3 and 4 are closed.

  D. The tank will empty entirely if Valves 1 and 2 are closed and Valves 4 and 5 are open.

  Correct Answer: D

  Because Valve 4 is above the bottom of the tank, some water will remain in the tank below the level of the valve, so the tank will never be completely empty.

• Question 115:

  

  For the valve shown in the figure above to open once each second, the cam must revolve at a rate of __________.

  A. 6 rpm

  B. 10 rpm

  C. 15 rpm

  D. 3 rpm

  Correct Answer: A

  Because 60 seconds comprise a minute, the valve must open 60 times per minute. The cam will open the

  valve 10 times per revolution, so 60 ÷ 10 = 6.

  The cam must make 6 revolutions per minute to raise the valve 60 times per minute.

• Question 116:

  Using a runner gives you a mechanical advantage of ___________.

  A. 4

  B. 2

  C. 3

  D. 1

  Correct Answer: B

  Using a runner (a single, moveable pulley) gives a mechanical advantage of 2.

• Question 117:

  The gas gauge in an auto relies on what mechanical device to measure the amount of gas in the tank?

  A. ball and cock

  B. automatic valve

  C. float

  D. mechanical switch

  Correct Answer: C

  A float indicates the level of liquid in a container.

• Question 118:

  A gear and pinion have a ratio of 4 to 1.

  If the gear makes 200 revolutions per minute, the speed of the pinion is __________.

  A. 50 rpm

  B. 800 rpm

  C. 400 rpm

  D. 200 rpm

  Correct Answer: B

  The pinion turns 4 times as often as the gear: 4 × 200 = 800.

• Question 119:

  

  If Gear 1 in the figure above makes 10 complete clockwise revolutions per minute, then __________.

  A. Gear 2 makes 2 clockwise revolutions per minute.

  B. Gear 3 makes 8 clockwise revolutions per minute.

  C. Gear 3 makes 30 clockwise revolutions per minute.

  D. Gear 3 makes 9 counterclockwise revolutions per minute.

  Correct Answer: B

  Gear 1 makes 10 clockwise revolutions per minute. Gear 2, which is half the size, makes 20 counterclockwise revolutions per minute. (The number of revolutions it makes is inversely proportional to its difference in size.) Gear 2 is half the size of Gear 1, so to determine the number of revolutions it makes, multiply the number of revolutions Gear 1 makes by the inverse of 1⁄2: 10 × 2⁄1 (or just 2) = 20. Gear 3 is 2.5 times the size of Gear 2. In other words, it is 5⁄2 the size of Gear 2. To determine the number of revolutions Gear 3 makes, multiply the inverse of 5⁄2 by the number of revolutions Gear 2 makes: 2⁄5 × 20. This can be stated as 20⁄1 (the number of revolutions Gear 2 makes per minute) × 2⁄5 (the fraction of revolutions Gear 3 makes) = 40⁄5 or 8 revolutions per minute.

• Question 120:

  

  In the figure above, assume the valves are all closed. Which valves need to be open to fill the tank entirely?

  A. 1 and 2 only

  B. 1 only

  C. 1, 2, and 3

  D. 2 only

  Correct Answer: A

  Valves 1 and 2 need to be open to fill the tank.