A&P GENERAL ORAL (ASA)41
What Constitutes A Capacitor? - ANSWERS-Two conductors separated by an insulator.
What is the purpose of a capacitor? - ANSWERS-It stores energy in electrostatic fields.
Does a capacitor in an AC circuit cause the current to lead or lag? - ANSWERS-It causes the
current to lead the voltage.
What is the basic unit of capacitance? - ANSWERS-The farad
Why should electrolytic capacitors not be used in an AC circuit? - ANSWERS-They are polarized
and will only pass current in one direction.
What is an example of an inductor used in a magneto? - ANSWERS-The coil
Does an inductor in an AC circuit cause the current to lead or lag the voltage? - ANSWERS-It
causes the current to lag behind the voltage.
How can you find the polarity of an electromagnet? - ANSWERS-Hold the magnet in your left
hand with your fingers encircling the coil in the directions electrons flow. The direction your
thumb is facing is the north pole.
What is meant by impedance? - ANSWERS-The total opposition to the flow of AC.
In what unit is impedance measured? - ANSWERS-Ohms
,What are 5 sources of electrical energy? - ANSWERS-Magnetism, Heat, Pressure, Chemical, &
Light
What is the basic unit of power in a DC circuit? - ANSWERS-Watt.
What is meant by kilowatt? - ANSWERS-1,000 watts
What is meant by Megawatt? - ANSWERS-1,000,000 watts
What is the formula for power in a DC circuit? - ANSWERS-PIE / Power = Voltage x Current (P=EI)
What is the relationship between mechanical and electrical power? - ANSWERS-1 horsepower =
746 watts
What is meant by true power in an AC circuit? - ANSWERS-It is the product of circuit voltage and
the current in phase with it.
What unit is true power expressed? - ANSWERS-Watts
What is meant by apparent power in an AC circuit? - ANSWERS-The product of circuit voltage
and circuit current.
In what unit is apparent power expressed? - ANSWERS-Volt-Amps
What is meant by reactive power in an AC circuit? - ANSWERS-The power consumed in the
inductive & capacitive reactances in an AC circuit.
,In what units is reactive power expressed? - ANSWERS-volt-amps reactive (VAR), and kilovolt-
amps reactive (KVAR)
What is meant by the power factor in an AC circuit? - ANSWERS-The ratio of true power to
apparent power.
Which law of electricity is the most important for an aircraft mechanic to know? - ANSWERS-
Ohms law.
what are the elements of Ohms law? - ANSWERS-voltage, current, resistance (EIR)
What is voltage? - ANSWERS-Electrical pressure.
What is the basic unit of voltage? - ANSWERS-Volt.
What instrument is used to measure voltage? - ANSWERS-A voltmeter.
To measure voltage, is the voltmeter placed in series or in parallel with the source voltage? -
ANSWERS-In parallel.
What is electrical current? - ANSWERS-The flow of electrons in a circuit.
What is the basic unit of current flow? - ANSWERS-Amps.
What part of an amp is a milliamp? - ANSWERS-One thousandth of an amp.
What instrument is used to measure current flow? - ANSWERS-Ammeter.
, What two things happen when current flows through a conductor? - ANSWERS-Heat is
generated and an electromagnetic field surround the conductor.
To measure current through a component, is an ammeter placed in series or parallel with the
component? - ANSWERS-Series.
What is meant by resistance in an electrical circuit? - ANSWERS-The opposition to the flow of
electrons.
What is the basic unit of electrical resistance? - ANSWERS-Ohm.
What is a Megohm? - ANSWERS-1,000,000 Ohms.
What 4 things affect the resistance of an electrical conductor? - ANSWERS-Length, Cross-
sectional size, Temperature, and Material.
What is used to measure electrical resistance? - ANSWERS-Ohmmeter.
How can you tell the resistance of a composition resistor? - ANSWERS-Series of color bands.
What is meant by continuity in an electrical circuit? - ANSWERS-The circuit is complete when
electrons can flow from one terminal of the power source to the other.
What instrument is used to measure continuity in an electrical circuit? - ANSWERS-Ohmmeter.
When measuring resistance of a component with an Ohmmeter, should the circuit be
energized? - ANSWERS-No.
What Constitutes A Capacitor? - ANSWERS-Two conductors separated by an insulator.
What is the purpose of a capacitor? - ANSWERS-It stores energy in electrostatic fields.
Does a capacitor in an AC circuit cause the current to lead or lag? - ANSWERS-It causes the
current to lead the voltage.
What is the basic unit of capacitance? - ANSWERS-The farad
Why should electrolytic capacitors not be used in an AC circuit? - ANSWERS-They are polarized
and will only pass current in one direction.
What is an example of an inductor used in a magneto? - ANSWERS-The coil
Does an inductor in an AC circuit cause the current to lead or lag the voltage? - ANSWERS-It
causes the current to lag behind the voltage.
How can you find the polarity of an electromagnet? - ANSWERS-Hold the magnet in your left
hand with your fingers encircling the coil in the directions electrons flow. The direction your
thumb is facing is the north pole.
What is meant by impedance? - ANSWERS-The total opposition to the flow of AC.
In what unit is impedance measured? - ANSWERS-Ohms
,What are 5 sources of electrical energy? - ANSWERS-Magnetism, Heat, Pressure, Chemical, &
Light
What is the basic unit of power in a DC circuit? - ANSWERS-Watt.
What is meant by kilowatt? - ANSWERS-1,000 watts
What is meant by Megawatt? - ANSWERS-1,000,000 watts
What is the formula for power in a DC circuit? - ANSWERS-PIE / Power = Voltage x Current (P=EI)
What is the relationship between mechanical and electrical power? - ANSWERS-1 horsepower =
746 watts
What is meant by true power in an AC circuit? - ANSWERS-It is the product of circuit voltage and
the current in phase with it.
What unit is true power expressed? - ANSWERS-Watts
What is meant by apparent power in an AC circuit? - ANSWERS-The product of circuit voltage
and circuit current.
In what unit is apparent power expressed? - ANSWERS-Volt-Amps
What is meant by reactive power in an AC circuit? - ANSWERS-The power consumed in the
inductive & capacitive reactances in an AC circuit.
,In what units is reactive power expressed? - ANSWERS-volt-amps reactive (VAR), and kilovolt-
amps reactive (KVAR)
What is meant by the power factor in an AC circuit? - ANSWERS-The ratio of true power to
apparent power.
Which law of electricity is the most important for an aircraft mechanic to know? - ANSWERS-
Ohms law.
what are the elements of Ohms law? - ANSWERS-voltage, current, resistance (EIR)
What is voltage? - ANSWERS-Electrical pressure.
What is the basic unit of voltage? - ANSWERS-Volt.
What instrument is used to measure voltage? - ANSWERS-A voltmeter.
To measure voltage, is the voltmeter placed in series or in parallel with the source voltage? -
ANSWERS-In parallel.
What is electrical current? - ANSWERS-The flow of electrons in a circuit.
What is the basic unit of current flow? - ANSWERS-Amps.
What part of an amp is a milliamp? - ANSWERS-One thousandth of an amp.
What instrument is used to measure current flow? - ANSWERS-Ammeter.
, What two things happen when current flows through a conductor? - ANSWERS-Heat is
generated and an electromagnetic field surround the conductor.
To measure current through a component, is an ammeter placed in series or parallel with the
component? - ANSWERS-Series.
What is meant by resistance in an electrical circuit? - ANSWERS-The opposition to the flow of
electrons.
What is the basic unit of electrical resistance? - ANSWERS-Ohm.
What is a Megohm? - ANSWERS-1,000,000 Ohms.
What 4 things affect the resistance of an electrical conductor? - ANSWERS-Length, Cross-
sectional size, Temperature, and Material.
What is used to measure electrical resistance? - ANSWERS-Ohmmeter.
How can you tell the resistance of a composition resistor? - ANSWERS-Series of color bands.
What is meant by continuity in an electrical circuit? - ANSWERS-The circuit is complete when
electrons can flow from one terminal of the power source to the other.
What instrument is used to measure continuity in an electrical circuit? - ANSWERS-Ohmmeter.
When measuring resistance of a component with an Ohmmeter, should the circuit be
energized? - ANSWERS-No.
