Free ASVAB Practice Tests | ASVAB Test Bank

Automotive Information

Which of the following regulates the opening and closing of the intake and exhaust valves in each cylinder in time with the motion of the piston?

camshaft

The camshaft is linked to the crankshaft through a timing belt and regulates the opening and closing of the intake and exhaust valves in each cylinder in time with the motion of the piston. An engine designated OverHead Camshaft (OHC) locates the camshaft in the cylinder head. An engine with Double OverHead Camshaft (DOHC) has two camshafts, one to regulate the intake valves and one to regulate the exhaust valves.

Mechanical Comprehension

Which of the following surfaces would have the lowest coefficient of friction?

ice

Coefficient of friction (μ) represents how much two materials resist sliding across each other. Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.

Word Knowledge

Ramble most nearly means:

roam

To wander, physically or in language.

Math Knowledge

Solve for z:
z² + 6z - 13 = -z + 5

2 or -9

The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

z² + 6z - 13 = -z + 5
z² + 6z - 13 - 5 = -z
z² + 6z + z - 18 = 0
z² + 7z - 18 = 0

Next, factor the quadratic equation:

z² + 7z - 18 = 0
(z - 2)(z + 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 2) or (z + 9) must equal zero:

If (z - 2) = 0, z must equal 2
If (z + 9) = 0, z must equal -9

So the solution is that z = 2 or -9

General Science

Which of the following states of matter exists at the lowest temperature?

solid

Solids exist at a lower temperature than liquids which exist at a lower temperature than gases.

General Science

Scalar quantities are fully described by which of the following?

a magnitude only

Velocity and displacement are vector quantities which means each is fully described by both a magnitude and a direction. In contrast, scalar quantities are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: \(\vec{v}\)

Shop Information

Which of the following would be used to make a drilling guide mark in a sheet of metal?

center punch

A punch is narrow and is used to drive objects like nails (pin punch) or for making guide marks for drilling (center punch) or patterns in wood or metal.

Electronics Information

Capacitors store:

electricity

Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.

General Science

Minerals, vitamins, and fiber are:

micronutrients

Minterals, vitamins, and fiber are micronutrients while proteins, carbohydrates, and fats are macronutrients.

Mechanical Comprehension

If the green box weighs 20 lbs. and is 1 ft. from the fulcrum, how much weight would need to be placed at the blue arrow to balance the lever if the arrow's distance from the fulcrum is 8 ft.?

2.5 lbs.

To balance this lever the torques on each side of the fulcrum must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

R_ad_a = R_bd_b

where a represents the left side of the fulcrum and b the right, R is resistance (weight) and d is the distance from the fulcrum.

Solving for R_b, our missing value, and plugging in our variables yields:

R_b = \( \frac{R_ad_a}{d_b} \) = \( \frac{20 lbs. \times 1 ft.}{8 ft.} \) = \( \frac{20 ft⋅lb}{8 ft.} \) = 2.5 lbs.