GENERAL CRANE SAFETY EXAM ACTUAL EXAM 200
QUESTIONS AND CORRECT DETAILED ANSWERS (ALL
POSSIBLE QUESTIONS AND CORRECT ANSWERS) |
AGRADE
What constitutes a capacitor? - ANSWER: Two conductors separated by an insulator.
What is the purpose of a capacitor? - ANSWER: It stores electrical energy in
electrostatic fields.
Does a capacitor in an AC cause the current to lead or lag the voltage? - ANSWER: It
causes the current to lead the voltage.
What is the basic unit of capacitance? - ANSWER: The farad.
Why should electrolytic capacitors not be used in an AC circuit? - ANSWER: They are
polarized, An electrolytic capacitor will pass current of one polarity, but will block
current of the opposite polarity.
What is meant by inductance? - ANSWER: The ability to store electrical energy in
electromagnetic fields.
What is the basic unit of inductance? - ANSWER: The henry.
What is an example of an inductor used in a magneto? - ANSWER: The coil.
Does an inductor in an AC circuit cause the current to lead or lag the voltage? -
ANSWER: It causes the current to lag behind the voltage.
How can you find the polarity of an electromagnet? - ANSWER: Hold the
electromagnet in your left hand with your fingers encircling the coil in the direction
electrons flow ( from negative to positive ). Your thumb will point to the north pole
of the electromagnet.
What is meant by impedance? - ANSWER: The total opposition to the flow of
alternating current. It is the vector sum of resistance, capacitive reactance and
inductive reactance.
In what units is impedance measured? - ANSWER: In Ohms.
What are five sources of electrical energy? - ANSWER: Magnetism, chemical energy,
light, heat and pressure.
What is the basic unit of power in a DC circuit? - ANSWER: The Watt.
,What is meant by kilowatt? - ANSWER: 1,000 watts.
What is meant by a megawatt? - ANSWER: 1,000,000 watts.
What is the formula for power in a DC circuit? - ANSWER: Power= Voltage times
Current (P = E • I).
What is the relationship between mechanical and electrical power? - ANSWER: 1
Horsepower = 746 Watts.
What is meant by true power in an AC circuit? - ANSWER: The product of circuit
voltage and the current that is in phase with this voltage.
In what units is true power expressed? - ANSWER: In watts.
What is meant by apparent power in an AC circuit? - ANSWER: The product of the
circuit voltage and the circuit current.
In what units is apparent power expressed? - ANSWER: In Volt-amps.
What is meant by reactive power in an AC circuit? - ANSWER: The power consumed
in the inductive and capacitive reactances in an AC circuit. Reactive power is also
called wattless power.
In what unit is reactive power expressed? - ANSWER: In volt-amps reactive (VAR), or
kilovolt-amps reactive (KVAR).
What is meant by power factor in AC circuit? - ANSWER: The ratio of true power to
apparent power. It is also the ratio of circuit resistance to circuit impendance.
Which law of electricity is the most important for an aircraft mechanic to know? -
ANSWER: Ohm's law.
What are the elements of ohm's law? - ANSWER: Voltage E, current I and resistance
R ( volts, amps and ohms).
What is voltage? - ANSWER: Electrical pressure.
What is the basic unit of voltage? - ANSWER: The volt.
What instrument is used to measure voltage? - ANSWER: A voltmeter
To measure voltage, is a voltmeter placed in series or in parallel with the source of
voltage? - ANSWER: In parallel.
What is electrical current? - ANSWER: The flow of electrons in a circuit.
,What is the basic unit of current flow? - ANSWER: The ampere (amp)
What part of an amp is a milliamp? - ANSWER: One thousandth (0.001) of an amp.
What instrument is used to measure current flow? - ANSWER: An ammeter.
What two things happen when current flows through a conductor? - ANSWER: Heat
is generated and a magnetic field surrounds the conductor.
To measure current through a component, is an ammeter placed in parallel or in
series with the component? - ANSWER: In series.
What is meant by resistance in an electrical circuit? - ANSWER: The opposition to the
flow of electrons.
What is the basic unit of electrical resistance? - ANSWER: The ohm.
What is a megohm? - ANSWER: One million (1,000,000) ohms.
What four things affect the resistance of electrical conductor? - ANSWER: The
material, the cross-sectional area, the length and the temperature.
What instrument is used to measure electrical resistance? - ANSWER: An ohmmeter.
How can you tell the resistance of a composition resistance? - ANSWER: By a series
of colored bands around one end of the resistor.
What is meant by continuity in an electrical circuit? - ANSWER: The circuit is
continuous (or complete) when electrons can flow from one terminal of the power
source to the other.
What is the instrument is used to measure continuity in an electrical circuit? -
ANSWER: An ohmmeter.
When measuring resistance of a component with an ohmmeter, should the circuit be
energized? - ANSWER: No, there should be no power on the circuit.
What are three things must an electrical circuit contain? - ANSWER: A source of
electrical energy, a load to use the energy and conductors to join the source and the
load.
What are three types of DC circuits with regard to the placement of the various
circuit components? - ANSWER: Series, parallel and series-parallel.
What is the name of the law that describes the relationship in an electrical circuit of
voltage, current and resistance? - ANSWER: Ohm's law.
, What is the basic equation of ohm's law? - ANSWER: E= I×R
What is used to find current when voltage and resistance are known? - ANSWER: I=
E/R
What formula is used to find resistance when voltage and current are know? -
ANSWER: R= E/I
What happens to the current in a DC circuit if the voltage is increased but the
resistance remains the same? - ANSWER: It increases.
What happens to the current in a conductor if the length of the conductor is doubled
with all other parameters unchanged? - ANSWER: It would decrease to one half.
What is the voltage across each resistor connected in parallel across a 12-volt
battery? - ANSWER: 12 volts.
How much current flows through each of three resistors connected in series if the
total current is 3 amps? - ANSWER: 3 amps.
What is the total resistance of three 12-ohm resistor connected in series? - ANSWER:
36 ohms.
What is the total resistance of three 12-ohm resistors connected in parallel? -
ANSWER: 4 ohms.
What is meant by the capacity rating of a lead-acid battery? - ANSWER: The number
of hours a battery can supply a given current flow.
In what units is battery capacity expressed? - ANSWER: In ampere-hours.
What electrolyte is used in a lead-acid battery? - ANSWER: A mixture of sulfuric acid
and water.
Does the specific gravity of the electrolyte in a lead-acid battery increase or decrease
as the battery becomes discharged? - ANSWER: It decreases.
What is the specific gravity of a fully charged lead-acid battery? - ANSWER: Between
1.275 and 1.300
How many cells are there in a 24-volt lead-acid battery? - ANSWER: 12
What is the range of temperature of the electrolyte in a lead-acid battery that does
not require a correction when measuring it's specific gravity? - ANSWER: Between
70°F and 90°F.
QUESTIONS AND CORRECT DETAILED ANSWERS (ALL
POSSIBLE QUESTIONS AND CORRECT ANSWERS) |
AGRADE
What constitutes a capacitor? - ANSWER: Two conductors separated by an insulator.
What is the purpose of a capacitor? - ANSWER: It stores electrical energy in
electrostatic fields.
Does a capacitor in an AC cause the current to lead or lag the voltage? - ANSWER: It
causes the current to lead the voltage.
What is the basic unit of capacitance? - ANSWER: The farad.
Why should electrolytic capacitors not be used in an AC circuit? - ANSWER: They are
polarized, An electrolytic capacitor will pass current of one polarity, but will block
current of the opposite polarity.
What is meant by inductance? - ANSWER: The ability to store electrical energy in
electromagnetic fields.
What is the basic unit of inductance? - ANSWER: The henry.
What is an example of an inductor used in a magneto? - ANSWER: The coil.
Does an inductor in an AC circuit cause the current to lead or lag the voltage? -
ANSWER: It causes the current to lag behind the voltage.
How can you find the polarity of an electromagnet? - ANSWER: Hold the
electromagnet in your left hand with your fingers encircling the coil in the direction
electrons flow ( from negative to positive ). Your thumb will point to the north pole
of the electromagnet.
What is meant by impedance? - ANSWER: The total opposition to the flow of
alternating current. It is the vector sum of resistance, capacitive reactance and
inductive reactance.
In what units is impedance measured? - ANSWER: In Ohms.
What are five sources of electrical energy? - ANSWER: Magnetism, chemical energy,
light, heat and pressure.
What is the basic unit of power in a DC circuit? - ANSWER: The Watt.
,What is meant by kilowatt? - ANSWER: 1,000 watts.
What is meant by a megawatt? - ANSWER: 1,000,000 watts.
What is the formula for power in a DC circuit? - ANSWER: Power= Voltage times
Current (P = E • I).
What is the relationship between mechanical and electrical power? - ANSWER: 1
Horsepower = 746 Watts.
What is meant by true power in an AC circuit? - ANSWER: The product of circuit
voltage and the current that is in phase with this voltage.
In what units is true power expressed? - ANSWER: In watts.
What is meant by apparent power in an AC circuit? - ANSWER: The product of the
circuit voltage and the circuit current.
In what units is apparent power expressed? - ANSWER: In Volt-amps.
What is meant by reactive power in an AC circuit? - ANSWER: The power consumed
in the inductive and capacitive reactances in an AC circuit. Reactive power is also
called wattless power.
In what unit is reactive power expressed? - ANSWER: In volt-amps reactive (VAR), or
kilovolt-amps reactive (KVAR).
What is meant by power factor in AC circuit? - ANSWER: The ratio of true power to
apparent power. It is also the ratio of circuit resistance to circuit impendance.
Which law of electricity is the most important for an aircraft mechanic to know? -
ANSWER: Ohm's law.
What are the elements of ohm's law? - ANSWER: Voltage E, current I and resistance
R ( volts, amps and ohms).
What is voltage? - ANSWER: Electrical pressure.
What is the basic unit of voltage? - ANSWER: The volt.
What instrument is used to measure voltage? - ANSWER: A voltmeter
To measure voltage, is a voltmeter placed in series or in parallel with the source of
voltage? - ANSWER: In parallel.
What is electrical current? - ANSWER: The flow of electrons in a circuit.
,What is the basic unit of current flow? - ANSWER: The ampere (amp)
What part of an amp is a milliamp? - ANSWER: One thousandth (0.001) of an amp.
What instrument is used to measure current flow? - ANSWER: An ammeter.
What two things happen when current flows through a conductor? - ANSWER: Heat
is generated and a magnetic field surrounds the conductor.
To measure current through a component, is an ammeter placed in parallel or in
series with the component? - ANSWER: In series.
What is meant by resistance in an electrical circuit? - ANSWER: The opposition to the
flow of electrons.
What is the basic unit of electrical resistance? - ANSWER: The ohm.
What is a megohm? - ANSWER: One million (1,000,000) ohms.
What four things affect the resistance of electrical conductor? - ANSWER: The
material, the cross-sectional area, the length and the temperature.
What instrument is used to measure electrical resistance? - ANSWER: An ohmmeter.
How can you tell the resistance of a composition resistance? - ANSWER: By a series
of colored bands around one end of the resistor.
What is meant by continuity in an electrical circuit? - ANSWER: The circuit is
continuous (or complete) when electrons can flow from one terminal of the power
source to the other.
What is the instrument is used to measure continuity in an electrical circuit? -
ANSWER: An ohmmeter.
When measuring resistance of a component with an ohmmeter, should the circuit be
energized? - ANSWER: No, there should be no power on the circuit.
What are three things must an electrical circuit contain? - ANSWER: A source of
electrical energy, a load to use the energy and conductors to join the source and the
load.
What are three types of DC circuits with regard to the placement of the various
circuit components? - ANSWER: Series, parallel and series-parallel.
What is the name of the law that describes the relationship in an electrical circuit of
voltage, current and resistance? - ANSWER: Ohm's law.
, What is the basic equation of ohm's law? - ANSWER: E= I×R
What is used to find current when voltage and resistance are known? - ANSWER: I=
E/R
What formula is used to find resistance when voltage and current are know? -
ANSWER: R= E/I
What happens to the current in a DC circuit if the voltage is increased but the
resistance remains the same? - ANSWER: It increases.
What happens to the current in a conductor if the length of the conductor is doubled
with all other parameters unchanged? - ANSWER: It would decrease to one half.
What is the voltage across each resistor connected in parallel across a 12-volt
battery? - ANSWER: 12 volts.
How much current flows through each of three resistors connected in series if the
total current is 3 amps? - ANSWER: 3 amps.
What is the total resistance of three 12-ohm resistor connected in series? - ANSWER:
36 ohms.
What is the total resistance of three 12-ohm resistors connected in parallel? -
ANSWER: 4 ohms.
What is meant by the capacity rating of a lead-acid battery? - ANSWER: The number
of hours a battery can supply a given current flow.
In what units is battery capacity expressed? - ANSWER: In ampere-hours.
What electrolyte is used in a lead-acid battery? - ANSWER: A mixture of sulfuric acid
and water.
Does the specific gravity of the electrolyte in a lead-acid battery increase or decrease
as the battery becomes discharged? - ANSWER: It decreases.
What is the specific gravity of a fully charged lead-acid battery? - ANSWER: Between
1.275 and 1.300
How many cells are there in a 24-volt lead-acid battery? - ANSWER: 12
What is the range of temperature of the electrolyte in a lead-acid battery that does
not require a correction when measuring it's specific gravity? - ANSWER: Between
70°F and 90°F.
