# Shared Flashcard Set

## Details

A&P
Oral Questions
45
Other
Professional
12/03/2011

Term
 What is the most important law applicable to the study of electricity?
Definition
 Ohm's law (I= E/R)
Term
 What are the elements of Ohm's Law?
Definition
 Voltage (E), current (I), and resistance (R)
Term
 What are the sources of electrical power?
Definition
 Mechanical (generator), chemical (Battery), Photoelectric (light), and thermal (heat)
Term
 What does an electrical circuit consist of?
Definition
 source, resistance in form of power consuming device and a conductor. (Wires)
Term
 What represents capacitance in an AC circuit?
Definition
 A capacitor. (condensor)
Term
 What is the function of a capacitor?
Definition
 To store electriciity
Term
 What is inductance?
Definition
 A voltage that is induced by magnetic flux lines in a coil in an AC circuit. The induced voltage is oposite in direction to the applied voltage, and opposes any change in alternating current.
Term
 What is impedance?
Definition
 The opposition for AC to flow caused by the combined effect of resistance, inductive reactance, and capacitive reactance in an AC circuit
Term
 What is the unit of memasurement of power in a DC circuit?
Definition
 The watt. Amperes time volts equals watts (P = I x E) 746 watts equals one horsepower.
Term
 What is the kilowatt?
Definition
 it is 1000 watts.
Term
 In a DC circuit, what occurs when voltage is increased while resistance remains constant?
Definition
 There will be an increase in current.
Term
 What are the three types of DC electrical circuits?
Definition
 They are series, parallel, and series parallel
Term
 A 24 volt lead-acid battery has how many cells?
Definition
 it has 12 cells. Each cell is rated at 2 volts.
Term
 What should be the specific gravity of the electrolyte in a fully charged lead-acid battery?
Definition
 It should be between 1.275 and 1.300
Term
 What instrument is used to determine the seccific gravity of electrolyte in a lead acid battery?
Definition
 A Hydrometer
Term
 Why can't a hydrometer be used to determine the charge of a nickel-cadmium battery?
Definition
 The specific gravity of the electrolyte in a nickel-cadmium battery does not change appreciably during charge or discharge of the battery
Term
 When using a hydrometer to check the charge of a lead-acid battery, at what temperatures must a correction factor be applied to the reading?
Definition
 Adjustments must be made if temperature of the electrolyte is above 90F or below 70F
Term
 What is electromagnetic induction?
Definition
 It is the transfer of electical energy by means of a magnetic field(lines of flux). This is the principle of transformer operation
Term
 How are battery compartments protected against corrosion?
Definition
 They are coated with a special corrosion resistant paint such as bituminous paint.
Term
 What should be the correct electrolyte level in a properly seviced battery?
Definition
 It should be approx 3/8 inched above the plates, the electrolyte level should be up to the hole in the baffle plate in each cell
Term
 What is paralleling generators?
Definition
 This is when two or more generators are oerated at the same time to supply power for a load that must be shared equally.
Term
 Describe a no-trip circuit breaker (tri free).
Definition
 A "trip free" breaker makes it impossible to manually hold the circuit closed when excessive current is flowing. (Pops when circuit gets hot and can't reset until it's cooled off)
Term
Definition
 No, the fumes from the lead-acid battery can contamminate the electrolyte in the ni-cad battery.
Term
 WHat type of lines are used on aircraft drawings to indicate hidden views, alternate positions and center lines?
Definition
 A hidden view line is a medium width line made up of "short dashes". It reresents an edge that cannot be seen when looking at the part from a secific position.Alternate Position lines are medium width lines compposed "one long and two short evenly spaced dashes". They are used to sho alternate postion of a part or the realative position of a missing part.Center lines are comosed of "alternate long and short dashes". indicate the center.
Term
 Define "tolerance" as used in aircraft drawings.
Definition
 The difference bewtween the plus and minus allowable dimension of a part.
Term
 Define "clearance" as used in acft drawings.
Definition
 Clearance is the dimension given for the space between parts
Term
 What information is given in the title block of a blueprint?
Definition
 The drawing number, the name of the part or assembly, the scale, the date, the name of the firm, the name of the draftsman, the checker, and the approving official.
Term
 Why are dimensions used, and how are they shown on acft drawings?
Definition
 Dimensions are solid narrow lines, broken at the midpoint for the insertion of measurements. They are used to indicate the size of the object.
Term
 How can a change to an acft drawing be identified?
Definition
 By its revision letter. The revision letters are usually listed in a table next to the title block or at one corner of the drawing.
Term
 What is a "bill of material" associated with aircraft blueprints?
Definition
 It is a list of materials and parts neccesary for fabrication or assembly of a component or system
Term
 Why are symbols used when drawing acft blueprints?
Definition
 Symbols are a type of shorthand used for drawing. They show the characteristics of a component with a minimum amount of drawing.
Term
 How many views are required to determine the shape of an object?
Definition
 Three views: Front, Top and Side.
Term
 What is the datum and its purppose when making weight and balance computations?
Definition
 It is an imaginaryvertical line or plain from which measurements are taken both forward and aft to determine the relative location of items in the acft. The datum is always specified by the manufacturer.
Term
 What is the purpose of weight and balance control?
Definition
 Safety and efficiency in flight
Term
 When computing weight and balance, what is the "moment" and how is it obtained?
Definition
 a moment is a force which tends to rotate the acft about its center of gravity. It is obtained by multiplying the weight of an item (pounds) by the distance of the item from the datum (inches). It is usually expressed in inch-pounds
Term
 What is the "arm" of an item and how is it obtained?
Definition
 The arm is the distance (in inches) an item is located either forward or aft of datum. It is obtained either by actual measurement or from the aircraft weight and balance records.
Term
 What is the "tare weight", and how is it handled when making weight and balance calculations?
Definition
 "Tare" is the weight of extra equipment used for weighing the acft such as chocks, blocks, jacks, and chains. Tare weight must be substracted from the scale readings in order to obtain the actual weight of the acft.
Term
 What is meant by minimum fuel and how is it calculated for W/B purposes?
Definition
 Minimum fuel is the amount of fuel that should be used in W/B computations when the acft is loaded for an extreme condition check. For a reciprocating engine airplane certified under FAR Part 23, this is the fuel neccesary to operate the engines for one half hour at maximum continuous power
Term
 What is meant by residual fuel?
Definition
 It is the fuel remaining in the tanks, lines, and engine after draining. Also called "undrainable" or "unusable". It is part of the acfts empty weight.
Term
 How would you determine the empty weight and empty weight CG of an acft which is has tricycle landing gear if all weight and balance records are missing?
Definition
 Reweigh the acft and calculate the new W/B.
Term
 What is ballast?
Definition
 Ballast is lead bars, metal plates, shot bags, sand bags, or other items of weight which are placed in the acft to attain a desired CG location
Term
 What is difference between fixed wing aircraft and helicopter cg range?
Definition
 The CG location in a helo is much more critical than fixed wing. The CG range in some helos is less than 3 inches.
Term
 When weighing an acft to determine the empty weight CG, what must you do with reagrd to the equipment which is normally carried in the acft?
Definition
 All operations equiment whether it is required, optional, or special equipment must be included in the acft's empty weight
Term
 Why do some manufacturers specify an empty CG even thought the acft is not operated at this empty weight?
Definition
 When the empty weight CG falls within the empty weight CG range, it is unneccesary to perform a W/B check if standard loading and seating arrangements are used.
Term
 Why must the acft category be considered when computing W/B?
Definition
 some airplanes are certified in both normal and utility categories. This means that maximum allowable gross weight differs depending on which category the acft will be operated in.
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