Abeka Science Chapter 15 Flashcards Preview

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Flashcards in Abeka Science Chapter 15 Deck (60):
1

What is electricity that flows in only one direction?

Direct current (DO)

2

What is electricity that flows first in one direction and then the other, reversing at regular intervals?

Alternating current (AC)

3

Electricity is either _______ or _________.

Static or current

4

True or False:
Electrons move from one place to another because of the attraction or repulsion between electric charges.

True

5

What is the force with which an electric current flows?

Voltage (aka electric potential or electromotive force)

6

What is the rate of the charge "flow" called?

Current

7

What is theSI unit of current?

The ampere

8

What energy used per unit time?

Power

9

True or False:
The amount of electrical energy used by an electric device depends on two factors: the power of the electrical current and the length of time that the device operates.

True

10

What is the amount of energy used when 1kW of power is used continuously for 1 hour?

kilowatt-hour

11

What is the flow of electrons or other charged particles from one place to another?

Current electricity

12

What are materials through which current flows easily called?

Conductors

13

What are materials through which current does not easily flow called?

Insulators

14

What are materials called that are neither good conductors or insulators?

semiconductors

15

What is the amount a certain object hinders electron flow called?

Resistance

16

What is the unit of resistance?

The ohm

17

When the energy used to overcome resistance is converted into heat, what is the resulting heat called?

Joule heat

18

What is the most important factor affecting the ease of current flow?

The type of material

19

What are the three factors affecting the ease of current flow?

Type of material, diameter of the conductor, and temperature

20

True or False: the length of the conductor does not affect resistance.

False: it affects resistance

21

What is a material that allows current to flow through it with no resistance at all?

A superconductor

22

What is the temperature called at which a material becomes a superconductor?

Critical temperature

23

What law states that the current flowing through a conductor is directly proportional to the voltage and inversely proportional to the resistance?
The equation is V = IR

Ohm's law

24

What is an electrical device designed to add resistance to a circuit called?

A resistor

25

What is the path that an electric current follows?

Electric circuit

26

What are the three parts of a simple electric circuit?

Source of current (battery or generator), set of conductors (usually wires) that carries the electrons around the circuit, and a load.

27

What is a device that transforms the energy of the electric current not another form of useful energy?

A load

28

What is a material that allows current to flow through it?

Superconductor

29

What are the four factors affecting th ease of current flow? What is the most important of these factors?

Type of the material, diameter of the conductor, length of conductor, and temperature.

30

What is the relationship between voltage, current, and resistance known as?

Ohm's Law

31

What is an electrical device designed to add resistance to a circuit called?

resistor

32

What is the path that an electric current follows?

An electric circuit

33

What is a circuit that contains a complete path for electrons to flow from the source of current, through the load, and back to the source called?

A closed circuit.

34

What is a device that transforms the energy of the electric current into another useful form of energy?

a load

35

What is it called when there is a gap in the circuit and the current flow ceases?

An open circuit

36

What is a device that opens or closes a circuit?

A switch

37

What occurs if electricity has the opportunity to take a shortcut through a circuit, avoiding the load?

A short circuit

38

What is the narrow strip of metal housed in a protective, insulated case?

A fuse

39

What is an automatic switch that opens the circuit when current flowing through it exceeds a predetermined amount?

A circuit breaker

40

In what kind of a circiit are the loads arranged so that the electric current flows thorugh each load after each other, adding the resistances together?

A series circuit

41

In what kind of circuit are loads arranged in separate branches of the circuit and the current is divided among them?

A parallel circuit

42

What was the first electric light suitable for household use that consists of a thin filament that is heated to a very high temperature?

Incandescant lamp

43

What lamp produces light by passing an electric current through a long tube filled with a low-pressure mixture of mercury vapor and argon?

Flourescent lamp

44

What is a flourescent lamp that is compacted into a coil?

Compact flourescent lamp (CFL)

45

What is an electric discharge lamp filled with neon gas instead of mercury vapor?

Neon lamp

46

What are semiconductor devices that emit light when a direct electric current is applied?

Light-emitting diodes (LEDs)

47

What is in its simplest form a wire coil with an iron bar free to slide back and forth?

solenoid

48

What is a switch, or key, at one end of a long wire and an electromagnet at the other end? It was used for early communication and incented by Samuel Morse.

telegraph

49

What is an electrical switch operated by an electromagnet?

a relay

50

What is a device that converts pulses of electrity into sound waves?

A loudspeaker

51

What is the most important device for converting electricity into motion?

electric motor

52

What is a group of electrochemical cells connected together as a single source of current?

A battery

53

What is the ability of magnetism to convert mechanical motion into electric current called?

electromagnetic induction

54

What is a device that uses electromagnetic induction to produce electricity?

generator

55

How can the strenth of an electromagnetically induced current be increased?

By moving the magnet more quickly, by increasing the strength of the magnet, and by increasing the number of coils.

56

What takes the place of a commutator in an AC motor?

slip rings

57

In what device does a conducting fluid pass throguh a magnetic field at high speed?

A magnetohydrodynamic generator (MHD generator)

58

What device increases or decreases the voltage of alternating current using electromagnetic induction?

a transformer

59

What transformer increases the voltage of a current? Which one decreases the voltage?

A step-up transformer; a step-down transformer.

60

What branch of the study of electricity deals with the behavor and motion of electrons in a vacuum or in special materials?

electronics