ENERGY CONVERSION/MOTORS/GENERATORS

Question 1

equivalent of or capacity of doing work

Answer 1

Energy

Question 2

transformation of energy from one form to another. Energy in the forms provided by nature that can be used such as electricity.

Answer 2

Energy conversion

Question 3

Two General Methods of Energy Conversions

Answer 3

1. Direct Energy Conversion
2. Dynamic Energy Conversion

Question 4

Static without mechanical motion

Answer 4

Direct energy conversion

Question 5

With Mechanical Motion

Answer 5

Dynamic energy conversion

Question 6

somestimes called static energy-conversion devices. Most of these energy converters use electrons as their working fluid.

Answer 6

Direct energy-conversion devices

Question 7

changes chemical energy directly into an electric current.

Answer 7

Electrochemical Cell

Question 8

converts sun light into electricity

Answer 8

Solar cell

Question 9

drives electrons across a potential difference at a semiconductor juction.

Answer 9

Radiant energy

Question 10

used junctions formed by coating selenium (a semiconductor) with an extremely thin layer of gold.

Answer 10

Genuine solar cell

Question 11

is often used interchangeably with photovoltaic cell, photocell, or photoelectric cell.

Answer 11

Solar cell

Question 12

(seedback effect) are devices that convert heat directly into electricity.

Answer 12

Thermoelectric generators

Question 13

generated when electrons are driven by thermal energy across a potential difference at the junction of two conductors made of dissimilar materials.

Answer 13

Electric current

Question 14

junction of two conductors made of dissimilar materials.

Answer 14

Thermocouple

Question 15

generate electricity when subjected to mechanical pressure.

Answer 15

Piezoelectric devices

Question 16

electrochemical producer of electricity. continuous operations is achved by feeding fuel(hydrogen) and an oxidizer(oxygen) to the cell and removing the reaction products.

Answer 16

Fuel cell

Question 17

direct energy converter with considerble potential. produces electricity directly from a high temperature, high pressure electrically conductive fluid (usually an ionized gas) moving through a strong magnetic field.

Answer 17

Magnetohydrodynamic

Question 18

the terminal voltage of the battery with no load connection.

Answer 18

Open circuit voltage

Question 19

the terminal voltage of the battery with load connection.

Answer 19

Operating voltage

Question 20

the capacity of the battery which tells us how long the battery can supply a given load.

Answer 20

Ampere hour

Question 21

when batteries are kept, the length of time under a specified condition that the battery retains its usability.

Answer 21

Shell life

Question 22

cell cannot be recharged, cannot restore chemical reaction, whose chemical reaction is not reversible.

Answer 22

Primary cell

Question 23

cell that can be recharged, can restore chemical reaction, whose chemical reaction is reversible.

Answer 23

Secondary cell

Question 24

cell that have a very long shelf life.

Answer 24

Reserve cell or battery

Question 25

mechanical rotating machine that converts mechanical energy to electrical energy or vice versa.

Answer 25

Dynamo

Question 26

reversible machine can be used as a motor or generator.

Answer 26

Gamme dynamo

Question 27

Battery Ratings

Answer 27

*Open Circuit Voltage *Operating Voltage *Ampere-hour *Shelf life

Question 28

DYNAMIC ENERGY CONVERSION-DEVICES

Answer 28

*Electrical Machines *Generators *Motors *Rotary Converters *Frequency Converter

Question 29

refer to rotating machines that convert energy from one form to another.

Answer 29

Electrical machines

Question 30

convert mechanical to electrical energy.

Answer 30

Generators

Question 31

convert electrical to mechanical energy.

Answer 31

Motors

Question 32

convert ac voltage to dc voltage, or vice versa.

Answer 32

Rotary converters

Question 33

convert ac voltage at one frequency to another ac voltage at another frequency.

Answer 33

Frequency converter

Question 34

Parts of Generators

Answer 34

*Prime Mover *Output Voltage

Question 35

the source of mechanical power energy used to turn the rotor of the generator.

Answer 35

Prime mover

Question 36

the output electrical energy that is the result of rotating the rotor of the generator.

Answer 36

Output voltage

Question 37

TWO IMPORTANT PARTS OF A GENERATOR

Answer 37

*Field poles *Armature winding

Question 38

even sets electromagnets or permanent magnets. Thi provides excitation or flux to the armature.

Answer 38

Field poles

Question 39

a laminated core with current-carrying copper wires. This will cut the flux supplied by the field poles.

Answer 39

Armature winding

Question 40

Dc generators

Answer 40

*Self-Eited Shunt Generator *separately exited shunt generator *Series Generators *Compound Generators Short and long shunt compound generators

Question 41

is the most important means of producing electrical power.

Answer 41

Ac generator

Question 42

Regardless of the size of ac generator they have two mechanical parts

Answer 42

*rotor *stator

Question 43

is the part that rotates

Answer 43

Rotor

Question 44

is the part that remains stationary

Answer 44

Stator

Question 45

armature is always the rotor

Answer 45

Dc generator

Question 46

the armature may be either rotor or stator

Answer 46

Alternators

Question 47

TYPES OF ALTERNATORS

Answer 47

1. Rotating-armature alternator 2. Rotating-field alternator

Question 48

This alternator is similar in construction to the dc generator in that he armature rotates in a stationary magnetic field.

Answer 48

ROTATING-ARMATURE ALTERNATOR

Question 49

The EMF generated in the armature windings converted from ac to dc means of the commutator.

Answer 49

DC GENERATOR

Question 50

The generated ac is brought to the load uncharged by means of slip rings. Generally not used to supply electric power in large quantities.

Answer 50

-ROTATING-ARMATURE ALTERNATOR

Question 51

The advantage of having a stationary armature winding is that the generated voltage can be connected directly to the load. A rotating armature requires slip rings and brushes to conduct the current from the armature to the load.

Answer 51

-ROTATING FIELD ALTERNATOR

Question 52

The prime movers is the source of the mechanical power that is required to turn the rotors of all generators, large or small, ac or dc.

Answer 52

-PRIME MOVERS

Question 53

The prime movers are divided into two classes of generators.

Answer 53

-HIGH SPEED AND LOW SPEED

Question 54

Examples of this prime movers are steam and gas turbine.

Answer 54

-HIGH SPEED

Question 55

Internal-combustion engines and electric motors are classified as one of the generators in prime movers.

Answer 55

-LOW SPEED

Question 56

In rotating field alternators

Answer 56

-ROTORS

Question 57

There are two types of rotors

Answer 57

1. TURBINE DRIVEN ROTOR 2. SALIENT-POLE ROTOR

Question 58

Has winding that are arranged to form two or four distinct poles. These windings are firmly embeded in slots to withstand the tremendous centrifugal forces encountered at high speeds.

Answer 58

-TURBINE-DRIVEN ROTOR

Question 59

Is used in low speed alternators it consists often of several separately wound pole pieces bolted to the frame of the rotor.

Answer 59

-SALIENT-POLE ROTOR

Question 60

Two essential parts in rotating generators

Answer 60

1. PERMANENT MAGNETS 2. ARMATURE WINDING

Question 61

The voltage generated at the armature winding is always ac.

Answer 61

-ELECTRICAL MACHINES

Question 62

Alternating EMF at the armature winding is converted to DC by the commutator.

Answer 62

-DC GENERATOR

Question 63

The armature winding is rotated with respect to a stationary magnetic field produced by electromagnets or permanent magnets.

Answer 63

-DC GENERATORS

Question 64

The electromagnets or permanent magnets (magnetic fields) are rotated with respect to the stationary armature winding.

Answer 64

-AC GENERATORS