ASVAB MECHANICAL COMPREHENSION 3 EXAM

PDF Download

ASVAB MECHANICAL COMPREHENSION #3 EXAM

QUESTIONS

Actual Qs and Ans - Expert-Verified Explanation -Guaranteed passing score -20 Questions and Answers

-Format: Multiple-choice / Flashcard

Question 1: The figure above represents a water tank containing water. The number 1 indicates an intake pipe and 2 indicates a discharge pipe. Of the following, the statement that is LEAST accurate is that the...

• tank will eventually overflow if water flows through the intake pipe at a faster rate than it

flows out through the discharge pipe.

• tank will empty completely if the intake pipe is closed and the discharge pipe is allowed

to remain open.

• water in the tank will remain at a constant level if the rate of intake is equal to the rate of

discharge.

• water in the tank will rise if the intake pipe is operating when the discharge pipe is

closed.

Answer:

B; If pipe 2 is open while pipe 1 is closed, then the level will drop to the lowest level of 2, leaving the volume below 2 still filled, having no way to discharge. All other statements are true.Question 2: The difference between the boiling point and the freezing point of water on the Celsius scale is...

• 112°

• 0°
• 180°
• 100°

Answer:

D; Boiling Point = 100°, Freezing Point = 0°, 100° - 0° = 100°.Question 3: In the figure shown above, what force must be applied to the 6-inch file scraper to pry up the lid of the paint can? Assume that the average force holding the lid is 50 pounds (disregard the weight of the file scraper).

• 10 pounds
• 20 pounds
• 30 pounds
• 40 pounds

Answer:

A; Let x= force that must be applied. 50 x 1= x times 5; 50=5x; x = 50/5= 10 Ibs.Question 4: The arm in the below diagram is balanced exactly, as shown. If nut A is removed entirely, then, in order to rebalance the arm, it will be necessary to turn nut...

• C toward the left.
• C toward the right.
• B up.
• B down.

Answer:

B; If nut A were removed, it would be necessary to move nut C to the right to counter-balance the loss of the weight of nut A.Question 5: What is the function of A and B in the crankshaft shown in the drawing?

• They strengthen the crankshaft by increasing its weight.
• They make it easier to remove the crankshaft for repairs.

• They are necessary to maintain the proper balance of the crankshaft.
• They hold grease for continuous lubrication of the crankshaft.

Answer:

C; The function of A and B in the crankshaft is to counterbalance the weight for smooth piston motion.

Question 6: The purpose of an air valve in a heating system is to...

• relieve the air from steam radiators.
• prevent pressure from building up in a room due to the heated air.
• control the temperature in the room.
• allow excessive steam pressure in the boiler to escape into the atmosphere.

Answer:

A; An air valve on a radiator removes air from the steam pipes. If air is trapped in the pipes, it prevents the steam from going to the radiator. This would prevent the radiator from producing heat.Question 7: Which of the following is correct if gear Z in the figure above is turned to the right (R)?

• Gear Y turns L, and gear X turns R.
• Gear Y turns R, and gear X turns R.
• Gear Y turns L, and gear X turns L.
• Gear Y turns R, and gear X turns L.

Answer:

A; Here, right (R) can be thought of as how a point on the axle would appear to be moving. If gear Z moves to the right, gear Y will move in the opposite direction, to the left; and gear X will move in the opposite direction from gear Y, to the right.Question 8: Neglecting friction, what is the mechanical advantage of using a single fixed pulley shown above?

• 1
• 2
• 3

• 4

Answer:

A; A single fixed pulley is actually a first-class lever with equal arms. The mechanical advantage, neglecting friction, is 1.Question 9: In the above figure, if pulley A is the driver and turns in direction 1, which pulley turns fastest?

• A
• B
• C
• D

Answer:

A; Pulley A has the smallest circumference and therefore turns the fastest.Question 10: The below illustration represents a pulley, with practically no friction, from which two 10-pound weights are suspended as indicated. If a downward force is applied to weight 1, it is most likely that weight 1 will...

• come to rest at the present level of weight

2.

• move downward until it is level with weight

2.

• pass weight 2 in its downward motion and then return to its present position.
• move downward until it reaches the floor.

Answer:

D; Newton's First Law of Motion states a body at rest will stay at rest unless acted on by an outside force. Conversely, a body in motion stays in motion unless acted on by an outside force. In this picture, both objects are at rest (equilibrium). When an outside force is added to weight 1, the equilibrium changes, moving the weight downward. Because the pulley has practically no friction, the weight strikes the floor.