pt elec Flashcards
what is static electricity?
a. the electricity in a capacitor
b. a state of charge caused by motion between materials
c. electricity that cannot ever move once produced.
d. the potential difference across a battery
b. a state of charge caused by motion between materials
what is the problem that affects alkaline batteries in aircraft?
a. they are harder to get electricity from.
b. although they have a good capacity they have a lower power to weight ratio compared to older types.
c. being alkaline, they can suffer from thermal runway if the temperature is not monitored during charging.
d. they have a tendency to switch between AC and DC involving the need for hybrid TRU/inverter switching systems
c. being alkaline, they can suffer from thermal runway if the temperature is not monitored during charging.
what is the difference between a battery and a cell?
a. batteries are acid and cells are alkaline
b. a battery consists of many cells
c. a cell is where the battery is kept
d. a cell is the same as a battery
b. a battery consists of many cells
explain the reason for electrical bonding.
a. to ensure that the whole aircraft is at the same potential and to help with the earth return path (UniPole)
b. to ensure the whole aircraft is at the same potential as the atmosphere
c. to ensure the various parts of the aircraft are held together immovably.
d. to ensure the Pilots cannot leave the flightdeck.
a. to ensure that the whole aircraft is at the same potential and to help with the earth return path (UniPole)
which of the following normally describes the effect of an OPEN circuit?
a. the relevant circuit breakers or fuses will trip, protecting the circuit against excessive current flow.
b. the resulting current is dependent on the low resistance within the open circuit.
c. the current in the circuit may increase to the point where overheating may occur.
d. the affected equipment will not function as it will not have any electrical power.
d. the affected equipment will not function as it will not have any electrical power.
the unit used for mechanical and electrical power is?
a. amp
b. joule
c. watt
d. coulomb
c. watt
in the event of a short circuit:
a. only a circuit breaker is suitable
b. no protection is necessary
c. only a fuse will work
d. a fuse or circuit breaker will protect the circuit
d. a fuse or circuit breaker will protect the circuit
the voltage regulator of a DC generator is connected in:
a. parallel with the shunt/parallel field coils
b. series with the armature
c. series with the voltage coils
d. series with the shunt/parallel field coils
d. series with the shunt/parallel field coils
which of the following statements is a correct representation of Ohms Law?
a. v = r/I
b. I = v/r
c. I = r/v
d. v=I/r
b. I = v/r
fuses are rated by:
a. the number of volts they will pass
b. their wattage
c. the number of amperes they will carry
d. their resistance measured in ohms
c. the number of amperes they will carry
why is voltage control necessary?
a. without it the voltage of the generator would vary with RPM and generator load
b. voltage control is only necessary if a generator is fitted not an alternator
c. without it the voltage of the generator would vary with RPM only.
d. without it the voltage of the generator would vary with generator load only.
a. without it the voltage of the generator would vary with RPM and generator load
what is important to have/be monitored with a Lithium Aircraft Battery. (select 3)
- capacity
- frequency
- current
- temperature
- voltage
- current
- temperature
- voltage
select the four types of Battery used in aircraft?
- lead acid
- lithium peroxide
- lithium polymer
- nickel-cadmium
- lithium-ion
- cadmium-polymide
- lead acid
- lithium polymer
- nickel-cadmium
- lithium-ion
what should be used to neutralise nickel cadmium battery spillage?
- mercury
- orange juice
- boric acid
- bicarbonate of soda
- boric acid
which of the following would increase the magnetic field size of a coil?
a. decreasing current
b. removing the iron core
c. heating the coil
d. increasing current
d. increasing current
electromagnetic induction is caused by:
a. the motion of a conductor across a magnetic field or the field moving through a conductor.
b. the application of electricity to a conductor.
c. the motion of a conductor along a magnetic field or the field moving with a conductor
d. the field across a capacitor.
a. the motion of a conductor across a magnetic field or the field moving through a conductor.
which of the following occurs when current flows through a conductor?
a. resistance
b. magnetism
c. static charge
d. impedance
b. magnetism
flying through what conditions are you most likely to build up excessive static electricity?
- cold air
- snow shower
- warm humid air
- humid air
- snow shower
if two electromagnetic fields were placed side by side, what would happen?
a. the two fields would interact to weaken or strengthen each other.
b. the two fields would weaken each other.
c. nothing would happen.
d. the two fields would strengthen each other.
a. the two fields would interact to weaken or strengthen each other.
in order for an electrical current to flow:
a. there must be an EMF or voltage and a closed circuit.
b. there must be an open circuit and no resistance.
c. there must be a fuse connecting the circuit breakers.
d. there must be an EMF or voltage and an open circuit.
a. there must be an EMF or voltage and a closed circuit.
current is?
a. coulombs per second
b. electromotive force
c. always zero in a closed circuit
d. voltage
a. coulombs per second
which of the following describes a DC alternator?
a. a device with a fixed armature and a rotating field. AC is covered to DC by a split ring commutator.
b. a device with a rotating armature and a fixed field. AC is converted to DC by a bridge rectifier.
c. a device with a rotating armature and a fixed field. AC is converted to DC by a commutator.
d. a device with a fixed armature and a rotating field. AC is converted to DC by a bridge rectifier.
d. a device with a fixed armature and a rotating field. AC is converted to DC by a bridge rectifier.
what does a DC generator use to convert AC to DC?
a. a transformer
b. an inverter
c. a split ring commutator
d. a bridge rectifier
c. a split ring commutator
if you had a problem on the aircraft with a system, and needed to power it down and back up, but there was no normal on/off switch, how could you achieve this?
a. circuit breakers may be used to reset aircraft systems/ computers in the event of a system failure (no procedure is required)
b. it is not possible to reset a system without a switch
c. by removing and disposing of the fuse
d. circuit breakers may be used to reset aircraft systems/computers in the event of system failure (when part of a described procedure)
d. circuit breakers may be used to reset aircraft systems/computers in the event of system failure (when part of a described procedure)
which of the following if large, most directly relates to the size of the magnetic field generator?
- voltage
- current
- resistance
- frequency
- current
