ELECTRICAL

Question 1

If the electrical loads exceed power available (airplane or external), ELMS _____.

A. generates EICAS warnings
B. automatically sheds nonessential systems
C. automatically deploys the RAT
D. automatically starts the APU

Answer 1

B. automatically sheds nonessential systems

Question 2

When AC power is removed from the airplane with the BATTERY switch ON, the PA system remains powered _____.

A. in flight or on the ground
B. if the IFE/PASS power switch is ON
C. on the ground for 10 minutes only
D. in flight only if the RAT deploys

Answer 2

A. in flight or on the ground

Question 3

What does the main DC electrical system use to produce DC power?

A. PMA’s
B. TRU’s
C. PMG’s
D. RAT

Answer 3

B. TRU’s

Question 4

Can you turn the battery off in flight?

A. No, the switch is inhibited.
B. Yes, if the battery charger is working normally.
C. Yes, the switch is not inhibited.
D. Yes, with the backup generator operational.

Answer 4

A. No, the switch is inhibited.

Question 5

Several events can cause the backup AC electrical system to operate automatically, one of these events is when _____.

A. the APU is inoperative
B. flaps are extended out of the UP position
C. the landing gear is down and locked
D. power to one or both main AC busses is lost

Answer 5

D. power to one or both main AC busses is lost

Question 6

The main battery charger, when powered, will power the _____.

A. the right flight control bus
B. APU battery charger
C. hot battery bus
D. the C1 and C2 TRU’s

Answer 6

C. hot battery bus

Question 7

The ground service bus is normally powered by the right main bus. The _____ and _____ are alternate sources of power.

A. left main bus, hot battery bus
B. APU generator, primary external power
C. battery bus, hot battery bus
D. left transfer bus, right transfer bus

Answer 7

B. APU generator, primary external power

Question 8

During power source transfers (such as switching from the APU generator to an engine generator) operating sources are momentarily paralleled to prevent power interuption _____.

A. on the ground
B. in the air
C. neither on the ground nor in the air
D. both on the ground and in the air

Answer 8

A. on the ground

Question 9

While on the ground, normally the IDG can be electrically disconnected from the main busses by selecting an external electric power source or _____.

A. by manually deselecting external power
B. by manually deselecting the backup generator system
C. by selecting the DRIVE DISC switch to OFF
D. by selecting the GEN CTRL switch to OFF

Answer 9

D. by selecting the GEN CTRL switch to OFF

Question 10

What does the illumination of a generator DRIVE light indicate?

A. The respective generator breaker is open.
B. High IDG oil pressure.
C. Low IDG oil pressure
D. Failure of a backup generator.

Answer 10

C. Low IDG oil pressure

Question 11

If an IDG is manually disconnected in flight with the DRIVE DISC switch, can the pilots reconnect it?

A. No, maintenance action is required on the ground.
B. Yes, by resetting the circuit breaker, then closing the DRIVE DISC switch.
C. Yes, by closing the DRIVE DISC switch.
D. Yes, by selecting ISLN for the respective bus and then closing the DRIVE DISC switch.

Answer 11

A. No, maintenance action is required on the ground.

Question 12

The _____ powers the AC standby bus if the left transfer bus is not powered.

A. left IDG
B. hot battery bus
C. main battery
D. standby inverter

Answer 12

D. standby inverter

Question 13

What are the components of the standby electrical system?

A. The AC backup generators, the Standby inverter, the RAT generator, and the Main battery.
B. The APU backup battery, the Main battery, Standby inverter, and the RAT generator.
C. The Main battery, Standby inverter, RAT generator, and the C1 and C2 TRU’s.
D. The Standby inverter, the RAT generator, the AC backup generator, and the C1 and C2 TRU’s

Answer 13

C. The Main battery, Standby inverter, RAT generator, and the C1 and C2 TRU’s.

Question 14

What causes the IDG drive to automatically disconnect from the engine?

A. High generator drive temperature.
B. A fault detected on the main bus.
C. Low IDG oil pressure.
D. High IDG oil pressure.

Answer 14

A. High generator drive temperature.

Question 15

The entire airplane AC/DC electrical load is supplied by _____.

A. any one main AC power source and the main battery
B. the RAT if both AC busses lose power
C. any one main AC power source
D. any two main AC power sources

Answer 15

D. any two main AC power sources

Question 16

The external AVAIL light means power is plugged in and _____.

A. not yet available
B. selected/connected
C. voltage and frequencies are within limits but not yet selected/connected
D. voltage and frequencies are within limits and selected/connected

Answer 16

C. voltage and frequencies are within limits but not yet selected/connected

Question 17

Pushing the CABIN/UTILITY power switch to OFF removes power from the _____.

A. ground handling bus
B. ground service bus
C. DC fuel pump
D. main battery charger

Answer 17

B. ground service bus

Question 18

What is the maximum altitude for APU start?

A. 22,100 feet
B. 10,100 feet
C. 35,100 feet
D. 43,100 feet

Answer 18

D. 43,100 feet

Question 19

If demand from the RAT exceeds capacity to provide hydraulic and electrical power, which has priority.

A. Electrical power - hydraulics are shed to ailerons and elevator only while maintaining electrical power to the TRU’s.
B. RAT output is always evenly shared between hydraulic and electrical power.
C. Electrical power always has priority over hydraulics.
D. Hydraulic power - electrical load is shed until satisfactory hydraulic pressure can be maintained.

Answer 19

D. Hydraulic power - electrical load is shed until satisfactory hydraulic pressure can be maintained.

Question 20

How does the APU generator compare to the IDG’s?

A. It is electrically identical to the IDG.
B. It provides higher output than either IDG.
C. It provides lower output than either IDG.
D. It develops lower voltage than either IDG.

Answer 20

A. It is electrically identical to the IDG.

Question 21

The backup generator system automatically powers the right transfer bus when _____.

A. the landing gear is down and locked
B. the airplane passes through 2500 feet RA on the approach
C. LOC is selected on the MCP
D. approach mode (APP) is selected

Answer 21

D. approach mode (APP) is selected

Question 22

Secondary external power can power the _____.

A. only the hot battery bus
B. only the left main bus
C. only the right main bus
D. left and right main busses

Answer 22

D. left and right main busses

Question 23

When the GEN CTRL switches are ON, the generator breaker is armed to close automatically when generator power is _____.

A. selected OFF
B. available
C. paralleled to prevent interruption
D. interrupted

Answer 23

B. available

Question 24

Pushing the IFE/PASS SEATS power switch to OFF removes power from what?

A. Nonessential instrument flight electronics components.
B. Passenger seats, excluding telephones.
C. Passenger seats, excluding personal computer power outlets
D. All inflight entertainment components

Answer 24

D. All inflight entertainment components

Question 25

Once one engine is started, with no other electrical source providing power and the BUS TIE switches are in AUTO, the _____ powers both main busses. A. IDG B. DC system C. AC system D. APU

Answer 25

A. IDG

Question 26

Each engine-mounted backup generator contains _____ permanent magnet generator(s) (PMG). A. 1 B. 2 C. 4 D. 3

Answer 26

B. 2

Question 27

If primary external power is powering one or both main busses, and then the APU is started, the APU automatically connects to _____ after reaching operating speed. A. the left and right main busses B. neither main bus C. the left main bus D. the right main bus

Answer 27

C. the left main bus

Question 28

Several items are powered by the ground handling bus, item(s) include the _____. A. forward and aft cargo doors B. miscellaneous cabin lights C. left forward fuel pump D. bulk cargo door

Answer 28

A. forward and aft cargo doors

Question 29

What happens to the APU and RAT when both transfer busses are lost in flight? A. The APU has to be started manually but the RAT automatically deploys. B. The APU starts automatically but the RAT has to be deployed manually. C. The APU automatically starts and the RAT automatically deploys. D. Nothing happens

Answer 29

C. The APU automatically starts and the RAT automatically deploys.

Question 30

The primary power source for the flight control DC electrical system are the _____ backup generator PMG's. A. right and center B. left and right C. left and hot battery bus D. left and center

Answer 30

B. left and right

Question 31

The primary power source for the flight control DC electrical system are the _____. A. ground handling busses B. PMG's C. transfer busses D. left and right hot battery busses

Answer 31

B. PMG's

Question 32

The _____ normally supply power to the flight control DC electrical system. A. transfer busses B. PMA's C. main busses D. PMG's

Answer 32

D. PMG's

Question 33

Inflight, when both BUS TIE switches are set to AUTO, the priority for powering the left and right main busses is the _____. A. APU generator, main battery bus, reespective IDG B. APU generator, respective IDG, opposite IDG C. respective IDG, APU generator, opposite IDG D. respective IDG, opposite IDG, main battery bus

Answer 33

C. respective IDG, APU generator, opposite IDG

Question 34

On the ground, power transfers are made without interruption, except when _____. A. switching between primary and secondary external power sources B. switching between APU and IDG while operating with a single source of external power C. switching between APU and secondary power D. any IDG switching occurs

Answer 34

A. switching between primary and secondary external power sources