A&P General (Electrical Applications)

After a full charge on the bench, you perform a hydrometer check on a customer's 24-volt battery. Whatshould the specific gravity read, as a minimum?

1.275

Engineers may derate a circuit breaker within a subsystem. The industry standard is 125%. In other words, continuousload is 80% of the breaker rating. If installed in this manner, a 20-amp breaker should see a continuous load no greaterthan ______.

16 amps

An AC power source can supply 26V and 10A to the primary of a transformer. The load on the secondary side runs on 180V and draws 1.5A. What transformer ratio is most appropriate?

1:7 step-up.

The Beechcraft B60 through serial number 445 came with a factory-installed Ni-cad battery. From 446 on,12-volt lead-acid batteries were factory-installed. An STC allows installation of the LA battery in earlier serialnumbers. During an inspection, how can you visually identify which type of battery is installed?

2 x 12; six caps; 20 cells

The Boeing 787 generators have a peak to peak output of 664.8 VAC, which provides an RMS output of howmany volts?

235

Within a 120 volt system, a 20-amp fuse will blow if a downstream component causes the circuit resistance to dropbelow ____ ohms

6 ohms

The U.S. Navy P-3 employs four (three engine-driven, one APU-driven) eight-pole, 115 VAC, 60 KVA, 400 Hz,three-phase brushless AC generators. At what rpm must these generators spin to accomplish this output?

6000

The time constant for capacitors states that

99% of the circuit voltage will be available in five constants.

What class of amplifier flows current for more than 50% of the input signal, and provides reasonable fidelity and efficiency

AB

How can you determine if a capacitor has failed?

An ohmmeter check shows low resistance.

When would you use the constant current method to charge an aircraft battery?

Bench only

What type of amplifier is not suitable for high quality audio, since it outputs only 50% of the input signal?

Class B

Which function of a GCU uses a logic circuit to determine if the generator and load bus voltages are withintolerance?

Differential voltage

A maximum of two fuel boost pumps can be wired to one circuit breaker.

False

With adequate ventilation, you may perform lead acid and Ni-Cad servicing in the same room.

False

In order to output 40kVA and 400 Hz at 6000 rpm, the 737-400 generator has how many pairs of poles?

Four

On an oscilloscope, the horizontal sweep of a sine wave is a measurement of what?

Frequency.

CSDs use either an electrically-controlled or flyweight-type of _______ to regulate output speed.

Governor

What three-phase AC motor is typically used for landing gear actuation?

Induction

Rubber or plastic are typically used as wire _______ in electrical installations.

Insulator

When performing a test-bench capacity test on a Gill 12-volt lead acid battery, what is the purpose of the 10-volt cutoff or end voltage?

It sets a limit for determining if the battery is still airworthy.

Which diode is not installed reverse-biased in a circuit?

Light Emitting Diode (LED)

From the schematic in the presentation, the Beechcraft King Air wing flaps have three positions; up, 15 degrees, anddown. What specific small electrical component trips/opens to stop the flaps at 15 degrees?

Microswitch

this is the symbol for. . .

OR gate

What type of switch uses a low-current electromagnet to throw its contacts?

Relay

This equation is used to determine the above circuit's point of maximum current flow. What is this point called?

Resonance.

What is not a characteristic of the lithium-ion battery?

Susceptible to memory effect.

Alumel and chromel are attached, then heated, creating an electrical current. This describes the operation of the

Thermocouple

The _______ is typically used to measure recip engine cylinder head temperature, employing two dissimilar metalconductors that generate a voltage proportional to the temperature.

Thermocouple

What type of transistor coupling is very efficient due to the application of mutual induction?

Transformer coupling

What oscilloscope control is used to make a waveform appear stationary, for clear viewing on the display?

Trigger

What instrument would one use to measure the unusable power in an AC pitch trim motor circuit?

Varmeter

This is the symbol for . . .

Zener Diode

A sine wave's maximum voltage is reached 90 degrees before the maximum current. This condition applies to

an inductive circuit.

The item that completes the ground return from a component to the airframe is the

bonding strap.

The common method of dissipating static electricity is through the use of ____ ____ in unison with ___ ___ on controlsurfaces.

bonding straps, static wicks

What type of DC generator maintains a relatively constant voltage no matter the load?

compound wound

The speed of a three-phase synchronous motor is dependent upon the __________.

frequency applied to the stator.

Many modern aircraft employ sensitive electronics that can be damaged by ESD; therefore you may be required towear a ____ ___ ___ during handling of an LRU

ground wrist strap

The loss of AC power that occurs within a transformer as magnetism begins to build in the core is called

hysteresis.

In a circuit comprising capacitors, inductors, and resistors, as the frequency is increased, _______ reactance increases as well.

inductive

Compound-wound generators utilize ______ to counteract field distortion.

interpoles

In an AC circuit, the usable voltage is determined by ______ and is called its ________.

multiplying the peak voltage by .707; effective value.

When potassium hydroxide is combined with _______, the chemical reaction promotes current flow in the presence of an applied voltage.

nickel and cadmium plates

After a flight, the pilot of a Beechcraft King Air reports that the second engine's starting time is excessive.You check the voltage of the Ni-cad battery, and it reads 24.5 volts. Does that rule out the battery? Why?

no, voltage depression/memory effect

The tachometer generator in a constant-speed drive sends a signal to a solenoid-operated hydraulic valve within the transmission to maintain a constant ________ of the alternator.

output frequency

Which type of jacket should you not wear when refueling, servicing oxygen, or handling sensitive electronics?

polyester

the electrolytein a Ni-cad battery is _____ _____, which can be neutralized with ___ ____.

pottassium hydroxide, boric acid

The ______ alternator contains a rotor that acts as an electromagnet once it receives DC excitation voltage.

revolving field

The electrolyte in a lead acid battery is _____ ____, which can be neutralized with ___ ____;

sulfuric acid, sodium bicarbinate;

A capacitive circuit would show

the current leading the voltage (lead)

An inductive circuit would show the

voltage leading the current (lag)