electricity final test 4, semester 2

66問 • 2年前

問題一覧

fill in the correct word “less” or “greater” in the following statement describing an LEDS colour. _____ than 1.9v produces infrared light ? • ____ than 1.9v and ____ than 4v = red, green and yellow light • _____ than 4v produces blue light

• LESS than 1.9v produces infrared light • GREATER than 1.9v and LESS than 4v = red, green and yellow light • GREATER than 4v produces blue light

LED ?

a semiconductor device that releases energy in the form of photons

zener diode

a semiconductor that allows current to flow in both directions

inverters

a device used to change DC to AC

RAT

a device used to generate power in an emergency

busbar

a strip of metal used to distribute electricity

transformer rectifier unit

steps down or up an AC voltage and Converts it to DC

diode

a semiconductor device that acts as a one-way valve for current flow

SCR

a device that is turned ON through “gate pulse” and can be used to “rectify” AC to DC

if a transistor is operating in its “Saturation Region” it acts like a ____ switch?

closed

if a transistor is operating in its “Cut-off Region” it acts like a ____ switch?

open

what are some reasons for using the APU?

• to pressurize the aircraft during a maintenance task • to provide electrical power when or if a GPU is not available • start engines • provide electrical power in flight • provide heating (heat) or cooling (air conditioning) of the cabin

what are the available positions for a “transport category aircraft” landing gear selector lever?

up, down, off

what does this image show?

a bridge rectifier

match the power source to the power consumer

• essential service = Generator and Battery • vital service = Battery • non-essential service = generator

which diode set-up, from the image above, will allow current to flow through the circuit? picture A or B?

what services are those which can be isolated in an “in-flight emergency” for load shedding purposes ?

non-essential

a ____ is used to distribute power across the electrical system

busbar

what is the state of the diode as tested in the image above?

shorted

what kind of transistor is this?

common-emitter

what type of transistor amplifier is this?

common-base

what type of transistor amplifier is this?

common-collector

what is a device that changes DC into AC called?

Inverter

in order to have a transistor operate as an amplifier within its active region how are the “base-emitter” and “base-collector” biased?

• base-emitter = forward biased • base-collector = reverse biased

in what position must the throttle switch blade move to in order to activate the gear horn?

Retarded

on the job scenario: the aircraft is parked in the hangar with power off. you walk into the flight deck to put power on by moving the battery switch to the “ON” position and then move the ground power switch to the “ON” position. you wait about 30 seconds before leaving the flight deck to make sure the aircraft powers up ok. just as you’re leaving you notice that the nose gear “down and locked light” is not illuminated

an out of Rig “nose down and locked proximity sensor”

what “physical safety devices” can be used to protect against the accidental retraction of landing gear during maintenance visits?

“down and locked” gear pins

how many available postions are there for a transport category aircraft landing gear selector lever?

what is the state of the diode as tested in the image above?

serviceable, good

8 ?

transfer bus 2

1 ?

GCB 1

7 ?

DC BUS 2

3 ?

BTB 2

TRU 3

4 ?

115V GEN BUS 2

5 ?

28V AC BUS 1

2 ?

TR 1

retractable landing gear systems use proximity switches or limit switches to indicate gear position. how can proximity switches be rigged?

add or remove shims

what does this image stand for?

B = transistor gain IC = collector current IB = base current

5 ?

transfer bus off light

transfer bus light off

APU gen light off

bus transfer switch

GRD power available light

APU gen on/off switch

GRD POWER on/off switch

landing gear circuits include a ____ switch that monitors ____ power?

throttle switch, engine power

if the engine power is ____ too ____, a “warning horn” is heard to alert the pilot to ____ the landing gear.

reduced, low, lower gear

what is the state of the diode as tested in the image above?

open

match the load service to the definition

• essential service = those required to ensure a safe flight in the event of an “in-flight emergency” • vital services = those which would be required after an emergency wheels up landing • non-essential = those which can be isolated in an in-flight emergency

what services are required to ensure a safe flight in an “in-flight emergency”

essential services

which power option is preferred while working on an aircraft?

external power

when performing maintenance on an aircraft, list 4 options to power the aircraft (electrical)

1. APU 2. GPU 3. engine generators 4. external power 5. battery

_____ services are those which would be required after an emergency wheels-up landing such as “emergency lighting” and crash switch operation of fire extinguishers

Vital services

where is the safety latch pin found?

safety solenoid

what does the safety solenoid control?

landing gear selector lever

what commands the safety solenoid?

control unit

when function checking the landing gear system, what indication is there to show the different stages of a retractable landing gear?

1. Red lights (movement / not-locked) 2. Green lights (down / locked) 3. no lights (up / locked)

transistor type?

NPN

transistor type?

PNP

what electromechanical lock prevents the landing gear from retracting while the aircraft is on the ground?

1. safety switch 2. weight on wheels switch 3. WOW switches 4. squat switches

a device that converts AC to DC and steps it up or down is called a ____? what is the acronym for this device

TRU, transformer rectifier

region 1?

saturation

region 2?

cutoff

region 3 ?

active

region 4 ?

breakdown

Composites test 2

Zachary Halycz · 54問 · 2年前

Composites test 2