Baker's A&P Oral and practical Study
guide General section
What is the most important law applicable to the study of electricity? - ANS-Ohm's Law
(V = I x R)
What are the elements of Ohm's Law? - ANS-Voltage (v), Current (I), Resistance (R)
What are 4 sources of electrical power? - ANS-Mechanical (generator/ alternator),
Chemical (battery), Photoelectric (light), and Thermal (heat)
What does an electrical circuit consist of? - ANS-A source of electrical pressure (EMF),
Resistance in the form of an energy consuming electrical device(light bulb), Conductors
to provide a path for electron flow (wires). (a Power source, a load, and a conductor
connecting the load and the power source)
What represents capacitance in an AC circuit? - ANS-A Capacitor
What is the function of a capacitor? - ANS-To store electricity
What is Inductance? - ANS-When voltage is induced by magnetic flux lines in a coil in
an AC circuit. The induced voltage is opposite in direction to the applied voltage, and
opposes any change in the alternating current.
What is impedance? - ANS-The total opposition for AC to flow caused by the combined
effect of resistance, inductive reactance, and capacitive reactance in an AC circuit.
What is the unit of measurement of power in a DC circuit? - ANS-The Watt.
amp x volt = watt,
how many watts are in 1 horsepower? - ANS-746 watts
What is a kilowatt? - ANS-1000 watts
In a DC circuit, what occurs when voltage is increased, while the resistance remains the
constant? - ANS-There will be an increase in current
,What are the 3 types of DC electrical circuits? - ANS-They are Series circuits, Parallel
circuits, and complex circuits (series-parallel)
A 24 volt lead-acid battery has how many cells, and what is each cell rated at? - ANS-It
has 12 cells, and each cell is rated at 2 volts
What should be the specific gravity of the electrolytes in a fully charged lead acid
battery? - ANS-It should be between 1.275 and 1.300
What instrument is used to determine the specific gravity of electrolyte in a lead acid
battery? - ANS-a Hydrometer
What can a hydrometer not be used to determine the charge of a nickel cadmium
battery? - ANS-The specific gravity of the electrolyte in a nickel cadmium battery does
not change appreciably during charge or discharge of the battery.
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? - ANS-Adjustments
must be made if the temperature of the electrolyte is above 90° F or Below 70°F
What is electromagnetic induction? - ANS-It is the transfer of electrical energy by means
of a magnetic field (lines of flux). Transferring voltage from one conductor to another
without physically touching
What is the principle of a transformers operation? - ANS-electromagnetic induction
How are battery compartments protected from against corrosion? - ANS-They are
coated with special corrosion resistant paint such as a bituminous paint, an asphaltic
(tar based) paint, or with polyurethane enamel.
What are the 3 types of paints used in a battery compartment? - ANS-Asphaltic paint,
bituminous paint, and polyurethane enamel paint.
What should be the correct electrolyte level in a properly serviced battery? - ANS-It
should be approximately 3/8 inches above the plates. if the battery has baffle plates
above the cell plates
In a properly serviced battery that has baffle plates above the cell plates, how high
should the correct electrolyte level be? - ANS-The electrolyte level should be up to the
hole in the baffle plate in each cell.
, What are paralleling generators, and how is the load distributed? - ANS-This is when 2
or more generators are operated at the same time to supply power for a load that must
be shared equally.
Describe a no-trip (trip-free) circuit breaker. - ANS-this type of breaker makes it
impossible to manually hold the circuit closed when excessive current is flowing through
the circuit. (the breaker pops when the circuit gets hot, and cant be reset until the circuit
has cooled off.)
Can Lead acid and Ni-cad batteries be stored together? - ANS-No, the fumes from the
lead acid battery can contaminate the electrolyte in the Ni-cad battery.
What types of lines are used on aircraft drawings to indicate hidden views? - ANS-this
line type is a medium width line made up of short dashes. it shows lines or edges that
can not be seen when looking at the part from a specific position.
What types of lines are used on aircraft drawings to indicate center lines? - ANS-thin
lines composed of alternating long and short dashes, and are used to indicate the
center of an object.
What types of lines are used on aircraft drawings to indicate alternate position lines? -
ANS-medium width lines composed of one long and two short evenly spaced dashes.
they show an alternate position of a part, or the relative position of a missing part.
Define "Tolerance" as used in aircraft drawings. - ANS-The difference between the plus
and minus allowable dimension of a part. (± of .005 =.010)
Define "Clearance" as used in aircraft drawings. - ANS-This is the dimension given for
the space between parts.
What information is given in the title block of a blueprint? (8 things) - ANS-1) the
drawing number, 2) the name of the part/assembly, 3) the scale, 4) the date, 5) the
name of the firm/company, 6) name of the draftsman, 7) the checker, and 8) the
approving official.
Why are dimensions used, and how are they shown on aircraft drawings? - ANS-They
are solid narrow lines, broken at midpoint for the insertion of measurements. They are
used to indicate the size of an object.
guide General section
What is the most important law applicable to the study of electricity? - ANS-Ohm's Law
(V = I x R)
What are the elements of Ohm's Law? - ANS-Voltage (v), Current (I), Resistance (R)
What are 4 sources of electrical power? - ANS-Mechanical (generator/ alternator),
Chemical (battery), Photoelectric (light), and Thermal (heat)
What does an electrical circuit consist of? - ANS-A source of electrical pressure (EMF),
Resistance in the form of an energy consuming electrical device(light bulb), Conductors
to provide a path for electron flow (wires). (a Power source, a load, and a conductor
connecting the load and the power source)
What represents capacitance in an AC circuit? - ANS-A Capacitor
What is the function of a capacitor? - ANS-To store electricity
What is Inductance? - ANS-When voltage is induced by magnetic flux lines in a coil in
an AC circuit. The induced voltage is opposite in direction to the applied voltage, and
opposes any change in the alternating current.
What is impedance? - ANS-The total opposition for AC to flow caused by the combined
effect of resistance, inductive reactance, and capacitive reactance in an AC circuit.
What is the unit of measurement of power in a DC circuit? - ANS-The Watt.
amp x volt = watt,
how many watts are in 1 horsepower? - ANS-746 watts
What is a kilowatt? - ANS-1000 watts
In a DC circuit, what occurs when voltage is increased, while the resistance remains the
constant? - ANS-There will be an increase in current
,What are the 3 types of DC electrical circuits? - ANS-They are Series circuits, Parallel
circuits, and complex circuits (series-parallel)
A 24 volt lead-acid battery has how many cells, and what is each cell rated at? - ANS-It
has 12 cells, and each cell is rated at 2 volts
What should be the specific gravity of the electrolytes in a fully charged lead acid
battery? - ANS-It should be between 1.275 and 1.300
What instrument is used to determine the specific gravity of electrolyte in a lead acid
battery? - ANS-a Hydrometer
What can a hydrometer not be used to determine the charge of a nickel cadmium
battery? - ANS-The specific gravity of the electrolyte in a nickel cadmium battery does
not change appreciably during charge or discharge of the battery.
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? - ANS-Adjustments
must be made if the temperature of the electrolyte is above 90° F or Below 70°F
What is electromagnetic induction? - ANS-It is the transfer of electrical energy by means
of a magnetic field (lines of flux). Transferring voltage from one conductor to another
without physically touching
What is the principle of a transformers operation? - ANS-electromagnetic induction
How are battery compartments protected from against corrosion? - ANS-They are
coated with special corrosion resistant paint such as a bituminous paint, an asphaltic
(tar based) paint, or with polyurethane enamel.
What are the 3 types of paints used in a battery compartment? - ANS-Asphaltic paint,
bituminous paint, and polyurethane enamel paint.
What should be the correct electrolyte level in a properly serviced battery? - ANS-It
should be approximately 3/8 inches above the plates. if the battery has baffle plates
above the cell plates
In a properly serviced battery that has baffle plates above the cell plates, how high
should the correct electrolyte level be? - ANS-The electrolyte level should be up to the
hole in the baffle plate in each cell.
, What are paralleling generators, and how is the load distributed? - ANS-This is when 2
or more generators are operated at the same time to supply power for a load that must
be shared equally.
Describe a no-trip (trip-free) circuit breaker. - ANS-this type of breaker makes it
impossible to manually hold the circuit closed when excessive current is flowing through
the circuit. (the breaker pops when the circuit gets hot, and cant be reset until the circuit
has cooled off.)
Can Lead acid and Ni-cad batteries be stored together? - ANS-No, the fumes from the
lead acid battery can contaminate the electrolyte in the Ni-cad battery.
What types of lines are used on aircraft drawings to indicate hidden views? - ANS-this
line type is a medium width line made up of short dashes. it shows lines or edges that
can not be seen when looking at the part from a specific position.
What types of lines are used on aircraft drawings to indicate center lines? - ANS-thin
lines composed of alternating long and short dashes, and are used to indicate the
center of an object.
What types of lines are used on aircraft drawings to indicate alternate position lines? -
ANS-medium width lines composed of one long and two short evenly spaced dashes.
they show an alternate position of a part, or the relative position of a missing part.
Define "Tolerance" as used in aircraft drawings. - ANS-The difference between the plus
and minus allowable dimension of a part. (± of .005 =.010)
Define "Clearance" as used in aircraft drawings. - ANS-This is the dimension given for
the space between parts.
What information is given in the title block of a blueprint? (8 things) - ANS-1) the
drawing number, 2) the name of the part/assembly, 3) the scale, 4) the date, 5) the
name of the firm/company, 6) name of the draftsman, 7) the checker, and 8) the
approving official.
Why are dimensions used, and how are they shown on aircraft drawings? - ANS-They
are solid narrow lines, broken at midpoint for the insertion of measurements. They are
used to indicate the size of an object.
