Jeppesen Oral- Chapter 3 (Basic Electricity) Flashcards Preview

General A&P FAA > Jeppesen Oral- Chapter 3 (Basic Electricity) > Flashcards

Flashcards in Jeppesen Oral- Chapter 3 (Basic Electricity) Deck (45)
Loading flashcards...
1

One kilowatt is equal to how many watts?

1000 watts?

2

What law describes the most fundamental or basic relationships in an electrical circuit?

Ohms law

3

What are the three elements in Ohm's law?

Voltage, current, resistance

4

How would you write ohms law as an equation?

E=IR R=E/I I=E/R

5

If the resistance in a DC circuit remains the same but the voltage doubles, what happens to the amount of current flowing in the circuit?

It also doubles

6

In DC circuits, what unit measures power?

Watts

7

What three elements are required to form an electrical circuit?

Source of power (EMF), consumer (load), Conductors to connect the two

8

DC circuits can take on of three forms or types. What are they?

Series, parallel, complex

9

A 24 volt lead-acid battery has how many cells?

12 cells

10

A fully charge lead-acid battery has a Specific gravity that varies between what two values?

1.275 and 1.3

11

You must apply a correction to the Specific gravity reading of the electrolyte of a lead-acid battery when the temperature is outside what two values?

less than 70F and more than 90F

12

What is the reason for having separate facilities for storing and servicing nickel-cadmium and lead-acid batteries?

To prevent cross contamination since the two electrolytes are chemically oposite

13

The state of charge of a nickel-cadmium battery cannot be determined by measuring the specific gravity of the electrolyte for what reason?

No real change of SPG when being charged or discharged

14

What is the principal advantage of AC current over DC current?

Power can be transferred over greater distances, can be transformed

15

What are the three causes of opposition to current flow in an AC circuit?

Inductive reactance, capacitive reactance, resistance

16

Define inductance?

Ability of a coil to produce a Back EMF

17

What component creates capacitance in an AC circuit?

A capacitor?

18

How does a capacitor store electricity?

Stored in the form of electrostatic charge (in a field that exists between two conductors separated by an insulator

19

What property of an AC circuit is defined by the term "impedance"?

Total opposition to current in an AC circuit

20

What are two reasons that might cause a nickel-cadmium battery to fail in delivering its rated capacity?

Faulty cells or cell imbalance

21

What electrical values are measured by a typical multi-meter?

voltage, current, resistance

22

What are five sources of electrical energy?

Magnetism, chemical energy, light, heat, and pressure.

23

What four things affect the resistance of an electrical conductor?

The material, the cross-sectional area, the length, and the temperature.

24

How can you tell the resistance of a composition resistor?

By a series of colored bands around one end of the resistor.

25

How can you find the polarity of an electromagnet?

Hold the electromagnet in your left hand with your fingers encircling the could in the directions the electrons flow. Your thumb will point to the north end of the electromagnet.

26

In what units is impedance measured?

In ohms.

27

What happens to the current in a DC circuit if the voltage is increased but the resistance remains the same?

The current increases.

28

How is a lead-acid battery compartment treated to protect it from corrosion?

Paint it with an asphaltic (tar-base) paint or with polyurethane enamel.

29

What is used to neutralize spilled electrolyte from a lead-acid battery?

A solution of bicarbonate of soda and water

30

How high should the electrolyte level be in a properly serviced lead-acid battery?

Only up to the level of the indicator in the cell