Chapter 4 Electrical Systems

Question 1

Electrons flow from the ___ to the ___ side

Answer 1

Negative, positive

Question 2

Electricity involves many terms that can be directly related to water plumbing. Voltage is comparable to, and can be thought of as, the ___ that pushes water through pipes. Current is the amount of ___ actually flowing through the pipes at any given time.

Answer 2

Pressure, Water

Question 3

The greater the ___ (voltage) in a line, the greater the amount of ___ (electric current) that flows.

Answer 3

Water pressure, water

Question 4

Using the water analogy, the alternator can be thought of as the ___ which provides water pressure to the ___ and the ___

Answer 4

Pump, primary bus, avionics bus

Question 5

A spinning alternator causes electric ___ to flow into the primary bus and through the electrical equipment. It then returns to its ___ sources in a manner similar to the tray in our water analogy. This tray is called the ___.

Answer 5

Current, original, electrical ground

Question 6

The electrical ground is not the ground upon which you stand. It’s usually the airplane’s …

Answer 6

metal frame

Question 7

A load meter is located between the ___ and the ___ of our water (electrical) system.

Answer 7

Pump (alternator), primary bus

Question 8

The load meter shows the ___ placed on the pump (alternator) by the airplane’s water (electrical) system.

Answer 8

water load (current)

Question 9

A zero reading on the load meter (a full left deflection) means that the water pump (alternator) ___ providing pressure to the primary bus.

Answer 9

isn’t

Question 10

A zero reading on the load meter means the alternator ___ providing electricity to the primary bus or there is ___ electrical current drawn by the airplane’s electrical equipment. This can happy when the ___ fails or all the airplane’s electrical equipment is turned off.

Answer 10

isn’t, no, alternator

Question 11

Amps are a measure of ___ flow.

Answer 11

current

Question 12

Circuit breakers protect electrical equipment and wires from receiving more ___ than they can safely handle

Answer 12

current

Question 13

In the actual electrical system, the battery ___ stores the electrical charge provided by the alternator.

Answer 13

chemically

Question 14

It’s the ___ which allows you to operate the airplane’s electrical equipment when the engine isn’t running or when the alternator fails in flight.

Answer 14

Battery

Question 15

a 35 amp hour battery should (in theory) provide ___ amps of continuous current to the electrical system for one hour

Answer 15

35

Question 16

While airplane batteries are rated at 12 or 24 volts, airplane electrical systems (their alternators) are rated for ___ or ___ volts.

Answer 16

14,28

Question 17

Between the positive terminal of the battery and the primary bus is an ammeter, called a ___ ammeter.

Answer 17

Charge-discharge

Question 18

As the name implies, the charge-discharge ammeter tells you if electrical current is flowing into or out of the ___

Answer 18

battery

Question 19

A positive deflection of the charge-discharge ammeter usually implied that the battery is being…

Answer 19

charged

Question 20

A negative needle deflection on the charge-discharge ammeter usually implies that the ___ is supplying the primary bus with electrical current

Answer 20

battery

Question 21

Normally, the needle of the charge-discharge ammeter should be resting near the ___ or ___ mark. This implies that the battery is neither being charged nor discharged (a good sign)

Answer 21

zero, center

Question 22

After startup, the battery is sure to be slightly drained. You can expect to see a ___ needle deflection of five, maybe sis or seven needle widths on the ammeter right after engine start

Answer 22

Positive (+)

Question 23

Most airplane operation manuals suggest that after approximately ___ of cruising flight, the ammeter needle should return to within a two-needle-width deflection from center on the positive (+) or charging side.

Answer 23

30 minutes

Question 24

Excess voltage resulting from a battery overcharge can ___ battery fluid (electrolyte), damaging the battery and possibly causing a battery

Answer 24

Boil off, fire

Question 25

A needle deflection on the ___ side means current is flowing out of the battery onto the primary bus

Answer 25

negative (-)

Question 26

Load meters provide impoartant indications about the health of the airplane's electrical system. Unlike charge-discharge ammeters, they are calibrated to reflect the actual ___ load placed on the alternator

Answer 26

ampere

Question 27

Load meters with a zero or full-left deflection indicate the alternator ___ providing current to the primary bus

Answer 27

isn't

Question 28

During flight with the electrical equipment in use, a full left deflection of the load meter needle is similar to a charge-discharge ammeter reading pointing to the ___ side of its scale.

Answer 28

negative (-)

Question 29

A load meter needle deflection the the right of the zero index represents the ___ drain on the alternator.

Answer 29

electrical current

Question 30

If you add all the electrical current used by the active electrical equipment, this sum should be equal to the amount of the load meter ___ deflection.

Answer 30

needle's

Question 31

Radios typically consume ___ amp(s) of current while receiving about ___ amp(s) while transmitting

Answer 31

one-half, 5

Question 32

With two radios, two nav radios, one electric gyro, a transponder and an autopilot in use, a 16 amp deflection should be shown on the load meter. A needle deflection less than 16 amps implies that the ___ isn't providing enough current to run the equipment

Answer 32

alternator

Question 33

Load meter needle deflections less than the summed amperage of active and properly working electrical equipment imply that the ___ will eventually be ___.

Answer 33

Battery, drained

Question 34

Supposed the load meter's needle deflection is greater than the needs of the electrical equipment. This can lead to...

Answer 34

Evaporating battery fluid or battery and electrical fires

Question 35

Voltage regulators or alternator control units (they're essentially the same thing) regulate the ___ output

Answer 35

Alternator's

Question 36

Voltage regulators help alternators maintain a ___ voltage output under varying RPM conditions

Answer 36

Constant

Question 37

Alternators need a little bit of electricity running through them before they'll start producing electricity. This small amount of electrical prime is called the ___

Answer 37

Alternator field current

Question 38

If your airplane has a low-voltage light, it can illuminate...

Answer 38

During low engine idle, and When the alternator has been taken offline

Question 39

If your airplane has a high-voltage warning light, it can activate:

Answer 39

When the alternator puts out excessive voltage and if the voltage regulator malfunctions.

Question 40

If you need the equipment that was disable by the popped circuit breaker, a good recommendation is to never reset the circuit breaker ___

Answer 40

More than one time

Question 41

Manually taking the alternator offline becomes and important consideration if ___ condition occurs and the circuitry doesn't ___ isolate the alternator.

Answer 41

An over voltage, automatically

Question 42

If the battery is dead, the ___ isn't going to work.

Answer 42

Alternator

Question 43

If the voltage regulator goes bad and the alternator produces too much voltage, you can take the alternator offline by pulling the ___ circuit breaker

Answer 43

Main alternator

Question 44

Turning off the alternator half of the mater switch on many airplanes will shut off the ___ field current flow, thus deactivating the ___

Answer 44

Alternator, alternator

Question 45

If faced with an errant voltage regulator in flight which forces you to deactivate the alternator, unload the system by turning off ___ equipment

Answer 45

all nonessential electrical