Plus printable tests, Q&A, and an ad-free upgrade. Have a suggestion? Please let us know what you want!
Take an ASVAB Practice Test
Sample Practice Test Questions
If this lever is in equilibrium with an effort force of 10.0 ft. lb. at the blue arrow and a resistance force of 3 ft. lb. at the green box, what is its mechanical advantage?
Mechanical advantage (MA) is the ratio by which effort force relates to resistance force. If both forces are known, calculating MA is simply a matter of dividing resistance force by effort force:
MA = \( \frac{F_r}{F_e} \) = \( \frac{3 ft.}{10.0 ft.} \) = 0.3
In this case, the mechanical advantage is less than one meaning that each unit of effort force results in just 0.3 units of resistance force. However, a third class lever like this isn't designed to multiply force like a first class lever. A third class lever is designed to multiply distance and speed at the resistance by sacrificing force at the resistance. Different lever styles have different purposes and multiply forces in different ways.
An arc-welder creates heat using:
high voltage electricity
Welding is a high-temperature process that involves melting the base metals in the objects to be joined to fuse them together. A filler metal is used to provide additional material to make up a joint that, depending on the weld type, can be stronger than the base materials alone. Oxyacetylene welding is a welding process that uses a torch fueled with oxygen and acetylene gases. Electric-arc welding utlizes electric current in a safer welding process (it doesn't involve burning explosive gases) that enables a wide variety of specialized applications like stick, MIG (metal inert gas), and TIG (tungsten inert gas) welding.
Which of the following saws would you use if you're cutting wood along the grain?
ripsaw
The ripsaw delivers maximum efficiency at cutting with or along the grain (ripping).
Materials like metals that transfer heat efficiently are called:
conductors
Heat is always transferred from warmer to cooler environments and conduction is the simplest way this transfer can occur. It is accomplished through direct contact between materials and materials like metals that transfer heat efficiently are called conductors while those that conduct heat poorly, such as plastic, are called insulators.
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
Doppler effect
The Doppler effect occurs when the source or listener (or both) of sound waves is moving. If they're moving closer together, the listener perceives the sound with a higher pitch and, when they're moving apart, the listener perceives the sound with a lower pitch.
According to Boyle's Law, pressure and volume are inversely proportional:
\( \frac{P_1}{P_2} \) = \( \frac{V_2}{V_1} \)
In this problem, V2 = 10 ft.3, V1 = 30 ft.3 and P1 = 6.0 psi. Solving for P2:
P2 = \( \frac{P_1}{\frac{V_2}{V_1}} \) = \( \frac{6.0 psi}{\frac{10 ft.^3}{30 ft.^3}} \) = 18 psi
The fluid reservoir stores the __________ that the master cylinder uses to maintain hydraulic pressure.
brake fluid
The fluid reservoir stores the brake fluid that the master cylinder uses to maintain hydraulic pressure.
Which of the following will increase the mechanical advantage of a second-class lever?
move the object being lifted closer to the fulcrum
A second-class lever is used to increase force on an object in the same direction as the force is applied. This lever requires a smaller force to lift a larger load but the force must be applied over a greater distance. The fulcrum is placed at one end of the lever and mechanical advantage increases as the object being lifted is moved closer to the fulcrum or the length of the lever is increased. An example of a second-class lever is a wheelbarrow.