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General Science

Which of the following is not true of light waves?

are mechanical waves

Unlike mechanical sound waves that require a physical medium for propagation, light waves are electromagnetic and can travel through empty space. Light waves are also much faster, travelling at 186,000 m/s vs. 343 m/s for sound waves.

Automotive Information

Piston rings are responsible for which of the following?

regulating oil distribution inside the cylinder

Cylinders act as a guide for the pistons that translate the heat energy of combustion into the mechanical energy necessary to move a vehicle. Piston rings seal the piston to the cylinder to contain combustion gases and also regulate the oil distribution between the piston and cylinder wall. A cylinder head closes in the top of the cylinder forming the combustion chamber which is sealed by a head gasket (head). The head provides space for air and fuel intake valves, exhaust valves, and mounts for spark plugs and fuel injectors.

Electronics Information

What's the overall power consumption of a piece of equipment that is rated for 7 amps at 60 volts?

420 W

Power is measured in watts (W) and 1 watt equals 1 ampere multiplied by 1 volt: P = \( V \times I \). For this problem, the equipment is rated for 7 amps (I) at 60 volts (V) so the equation becomes P = \( 60 \times 7 \) = 420 W

General Science

Antigens in the blood determine:

blood type

Blood is categorized into four different types (A, B, AB, and O) based on the type of antigens found on the outside of the red blood cells. Additionally, each type can be negative or positive based on whether or not the cells have an antigen called the Rh factor.

Mechanical Comprehension

A screw is most like which of the following other simple machines?

inclined plane

A screw is an inclined plane wrapped in ridges (threads) around a cylinder. The distance between these ridges defines the pitch of the screw and this distance is how far the screw advances when it is turned once. The mechanical advantage of a screw is its circumference divided by the pitch.

Word Knowledge

Methodical most nearly means:

systematic

Performed in an orderly manner.

Math Knowledge

This diagram represents two parallel lines with a transversal. If d° = 140, what is the value of b°?

140

For parallel lines with a transversal, the following relationships apply:

angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°)
alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°)
all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other
same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°)

Applying these relationships starting with d° = 140, the value of b° is 140.

Electronics Information

The valence shell of a semiconductor is how full of electrons?

half full

Semiconductors have valence shells that are exacly half full and can conduct electricity under some conditions but not others. This property makes them useful for the control of electrical current.

General Science

An element in the physical state of __________ maintains a constant volume and shape.

solid

An element in a solid state has atoms or molecules that are constricted and do not move freely. Solids maintain a constant volume and shape and exist at a lower temperature than liquids or gases.

Automotive Information

What function does a two-stroke cycle engine perform on the second stroke?

combustion and exhaust

The two strokes of a two-stroke cycle engine are fuel intake and compression then combustion and exhaust.