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Electronics Information

Using a fuse with a current rating higher than that required by a circuit:

makes the circuit less safe

A fuse is a type of low resistance resistor that stops current flow in a circuit in response to a larger than intended electric current flow. Using a fuse with a higher current rating than required by a circuit is less safe as it could potentially allow overcurrent and risk a fire or heat-related equipment damage.

General Science

Cirrus clouds generally occur in what kind of weather?

fair

Cirrus clouds are thin, wispy high-altitude clouds composed of ice crystals that originate from the freezing of supercooled water droplets. Cirrus clouds generally occur in fair weather and point in the direction of air movement at their elevation.

Mechanical Comprehension

What's the first gear in a gear train called?

driver gear

A gear train is two or more gears linked together. Gear trains are designed to increase or reduce the speed or torque outpout of a rotating system or change the direction of its output. The first gear in the chain is called the driver and the last gear in the chain the driven gear with the gears between them called idler gears.

General Science

Convert -20C° to F°.

-4

To convert from C° to F° use:

\(F° = {9 \over 5}C° + 32\)

\(F° = {9 \over 5}(-20) + 32\)

\(F° = {-180 \over 5} + 32\)

\(F° = -36 + 32 = -4\)

General Science

Which of the following does not filter air as part of the respiratory system?

epiglottis

After air enters through the nose, it passes through the nasal cavity which filters, moistens, and warms it. Further filtering takes place in the pharynx, which also helps protect against infection, and then in the trachea which is just past the epiglottis which prevents food from entering the airway.

Mechanical Comprehension

If input effort is 700 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 5?

3500 ft⋅lb

Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 5 will multiply an input effort of 700 ft⋅lb by 5 to produce an output effort of 3500 ft⋅lb.

Automotive Information

Cylinder air and fuel intake valves, exhaust valves, and mounts for spark plugs and fuel injectors are contained in the:

head gasket

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.

Word Knowledge

Fidelity most nearly means:

loyalty

State of being faithful.

Mechanical Comprehension

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?

0.3

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.

Word Knowledge

Defiant most nearly means:

impudent

Showing bold resistance.