ASVAB ASVAB-SECTION-3 Online Practice Questions and Exam Preparation

ASVAB ASVAB-SECTION-3 Online Questions & Answers

• Question 11:

  Which of the following is not a simple machine?

  A. Lever
  B. Inclined plane
  C. Axe
  D. Pulley
  C. Axe

  ---

  An axe is a compound machine: the handle is a lever, and the head is two inclined planes (each side of the blade edge).

• Question 12:

  As the central shaft in the illustration below spins faster in a clockwise direction, the balls labeled A and B will ___________.

  

  A. move outward and downward
  B. move outward and upward
  C. move up
  D. move down
  B. move outward and upward

  ---

  Centrifugal force from the spinning shaft, regardless of direction, will cause the balls to move outward, away from the shaft; the tension on the strings holding them will result in the balls moving upward.

• Question 13:

  Helical gears have ___________.

  A. straight teeth
  B. slanted teeth
  C. teeth of unequal size
  D. no advantage over spur gears
  B. slanted teeth

  ---

  The teeth of helical gears are slanted.

• Question 14:

  If a first class lever with a resistance arm measuring 2 feet and an effort arm measuring 8 feet are being used, what's the mechanical advantage?

  A. 2
  B. 4
  C. 6
  D. 1
  B. 4

  ---

  Mechanical advantage can be calculated as Length of Effort Arm ÷ Length of Resistance Arm. MA = 8 ÷ 2 = 4.

• Question 15:

  What is the advantage of using wheels and axles?

  A. Wheels and axles provide greater power, enabling workers to achieve greater results with less effort.
  B. Wheels and axles are responsible for bearing the brunt of difficult lifting.
  C. Wheels and axles are not beneficial.
  D. Wheels and axles create a more effective conveyor belt effect.
  A. Wheels and axles provide greater power, enabling workers to achieve greater results with less effort.

• Question 16:

  If Pulley A is the driver and turns counterclockwise, which pulley will turn the slowest?

  

  A. Pulley A
  B. Pulley B
  C. Pulley C
  D. Pulley D
  D. Pulley D

  ---

  The pulley that is the largest will turn most slowly.

• Question 17:

  What purpose does an inclined plane serve?

  A. An inclined plane is a tilted surface designed to aid in supporting or transporting a load.
  B. Inclined planes are not useful implements and have been replaced by more effective methods of transportation.
  C. Inclined planes are tilted surfaces designed to assist in suspension.
  D. An inclined plane is intended to aid only in unloading merchandise.
  A. An inclined plane is a tilted surface designed to aid in supporting or transporting a load.

• Question 18:

  What are the potential functions of gear systems?

  A. Gears may be used to change direction in machinery and can be used to increase speed.
  B. Gears possess a single function: transmitting motion.
  C. The potential functions of gears are: changes in direction, speed changes (both increases and decreases), and motion transmission.
  D. Gears are primarily used for making changes in speed, but may also be used to instigate motion in machinery.
  C. The potential functions of gears are: changes in direction, speed changes (both increases and decreases), and motion transmission.

• Question 19:

  The force produced when two objects rub against each other is called __________.

  A. gravity
  B. recoil
  C. magnetism
  D. friction
  D. friction

  ---

  Objects rubbing together produce friction.

• Question 20:

  When forces act in pairs they are ___________.

  A. equal in magnitude and opposite in direction
  B. equal in magnitude and in the same direction
  C. equal in magnitude
  D. unequal in magnitude
  A. equal in magnitude and opposite in direction

  ---

  Since it is impossible to have one force unless it acts as one of a pair of forces, it means that these forces must be equal in magnitude and opposite in direction.