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

ASVAB ASVAB-SECTION-3 Online Questions & Answers

• Question 21:

  Force is something that can change the velocity of an object by making it __________.

  A. start or stop
  B. speedup
  C. slow down
  D. all of the above
  D. all of the above

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  Force is something that can change the velocity of an object by making it start or stop, speed up, or slow down. This means that all the answers given are correct.

• Question 22:

  A wood tool, a silver tool, and a steel tool are placed in boiling water for cleaning. Which tool gets the hottest?

  A. steel
  B. wood
  C. silver
  D. All three are equally hot.
  C. silver

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  Silver is the best conductor, so it becomes hottest.

• Question 23:

  The purpose of mechanical comprehension is __________.

  A. to inform workers on the proper use and function of machines
  B. to determine how to adequately use mechanic's tools
  C. to learn the use of various mechanisms
  D. to describe the training undergone by car mechanics
  A. to inform workers on the proper use and function of machines

• Question 24:

  

  In the figure above, assume the valves are all open.

  Which valves need to be closed for the tank to fill up completely?

  A. 3 and 4 only
  B. 3, 4, and 5
  C. 2, 3, and 4
  D. 4 only
  A. 3 and 4 only

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  Closing only Valves 3 and 4 keeps the water from leaving the tank.

• Question 25:

  When a football is thrown upwards in the air, what causes it to arc back towards the ground?

  A. Centrifugal force
  B. Gravity
  C. Friction
  D. Wind resistance
  B. Gravity

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  Gravity is the force that causes objects to be pulled back towards the earth.

• Question 26:

  In the pulley system shown, which pulley will rotate the fastest?

  

  A. Pulley A
  B. Pulley B
  C. Pulley C
  D. They will all rotate at the same speed.
  B. Pulley B

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  Pulley B will rotate the fastest. Just like meshing gears, the smaller the pulley in a system, the fester it rotates.

• Question 27:

  

  A runner is being used in the figure shown.

  How much effort (disregard friction, wind resistance, and the weight of the pulley and the rope) is using the cat lover lifting the 50-pound crate (with cat)?

  A. 50-pound effort
  B. 100-pound effort
  C. 25-pound effort
  D. 10-pound effort
  A. 50-pound effort

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  Stationary pulleys give no mechanical advantage, so effort equals the weight of the crate or 50 pounds.

• Question 28:

  

  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.

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

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  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 29:

  A __________ should be applied if gear shafts are not parallel to one another.

  A. shifting gear
  B. third gear
  C. bevel gear
  D. stopping gear
  C. bevel gear

• Question 30:

  Water in an engine can cause damage in winter weather because __________.

  A. it can vaporize
  B. water expands when it freezes
  C. ice is heavier than water
  D. cold water creates more steam than warm water
  B. water expands when it freezes

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  Water expands when it freezes, possibly damaging engine components.