Electricity 15: Concepts, terms, and SI Units

Question 1

Electricity that flows in only one direction is…

Answer 1

DC or Direct Current

Question 2

Continually alternates direction (current)

Answer 2

AC Alternating Current

Question 3

Why do electrons move from one place to another?

Answer 3

Because of the attraction and repulsion between electric charges

Question 4

Does the wire carrying a current have an overall charge?

Answer 4

NO

Question 5

The force with which an electric current flows is…

Answer 5

voltage

Question 6

What is the SI unit of voltage?

Answer 6

volt

Question 7

What is an instrument that measures voltage ?

Answer 7

voltmeter

Question 8

What is the amount of charge flowing past a given point in a certain amount of time? ( Rate of charge flow)

Answer 8

Current

Question 9

What is the SI unit of current?

Answer 9

Ampere —or informally the amp

Question 10

What is the instrument that measures current

Answer 10

ammeter

Question 11

What is the energy used per unit time; what is the formula that goes along with it? What is the SI unit?

Answer 11

Power;
P= VI; Power= Voltage(Current)
Watt

Question 12

The amount of electrical energy used by the electrical device can be described by what term? And what is the formula for it (basically)?

Answer 12

The kilowatt-hour

kW•hr = power/ amount of time used (in hours)

Question 13

What are objects that conduct electricity well?

Answer 13

conductor

Question 14

Materials that do not carry current well are

Answer 14

insulator

Question 15

If objects neither conduct or insulate… what are they?

Answer 15

Semiconductors

Question 16

The amount a certain object hinders electron flow is

Answer 16

resistance

Question 17

The unit of resistance is the

Answer 17

ohm, symbolized by omega

Question 18

The instrument to measure resistance is the

Answer 18

ohmmeter

Question 19

the energy used to overcome resistance is

Answer 19

Joule heat

Question 20

What are the four factors that can reduce resistance

Answer 20

Type of material
Length of conductor
Diameter of conductor
Temperature

Question 21

What law states that the current flowing through a conductor is directly proportional to the voltage and inversely proportional to the resistance? What is the formula stated out?

Answer 21

Ohm’s law

V= IR Voltage=Current(Resistance)

Question 22

any electrical device designed to add resistance to a circuit is the

Answer 22

resistor

Question 23

the path of electrical current is

Answer 23

electrical circuit

Question 24

What three parts do an electrical circuit contain? 
Hint: 
May be a battery or generator
Carries electrons around the circuit
Transforms energy into useful energy

Answer 24

Source of current
Conductors
Load

Question 25

A circuit that contains a complete path for the electrons to follow is a One that does not allow for complete flow?

Answer 25

closed circuit | open circuit

Question 26

the flow of current through a circuit can be controlled by a

Answer 26

switch

Question 27

a narrow strip of metal housed in a protective case that cannot be replaced after blowing out is a

Answer 27

fuse

Question 28

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

Answer 28

circuit breaker

Question 29

Fuses and circuit breakers not only help with short circuits, but also they help a situation when there are too many appliances plugged in to one circuit

Answer 29

overloaded circuit

Question 30

There is another method of safety with circuits to prevent electrocution

Answer 30

grounding

Question 31

Series Circuit | What is it’s relation to resistance voltage and current?

Answer 31

Current — Same Resistance — equals the resistances of all the loads added up Voltage — divided amongst the loads

Question 32

Parallel | What is the relation between current, resistance and voltage?

Answer 32

Current— divided among the loads Resistance — the total resistance is decreased as more loads are added in parallel to the circuit Voltage— the same throughout

Question 33

What produces light by heating a thin wire or filament to extremely hot?

Answer 33

Incandescent lamp

Question 34

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

Answer 34

Fluorescent lamp

Question 35

What produces light by using semiconductors when direct current is applied

Answer 35

LEDs, or light-emitting diodes

Question 36

what converts electricity to back and forth motion ; Describe it

Answer 36

Solenoid | A wire with an iron coil with an iron bar free to slide — with a ball

Question 37

an electrical switch operated by an electromagnet is a ...

Answer 37

relay

Question 38

What are the three main parts of the DC Motor? | What are the last part used for ?

Answer 38

Field magnet Armature Commutator The commutator is used for reversing the current

Question 39

What are the three main parts of the AC Motor? | What is the last one used for?

Answer 39

Field Magnet Armature Slip Rings They are used for not getting the wires tangled up

Question 40

The negative terminal contacts the cell’s... | The positive terminal contacts the cell’s ...

Answer 40

anode | cathode

Question 41

cells can be arranged in series to boost ...

Answer 41

voltage

Question 42

a group of electrochemical cells connected as a single source of current is the ...

Answer 42

Battery

Question 43

cells can be arranged in parallel to boost the...

Answer 43

current

Question 44

The ability of magnetism to convert mechanical motion into electric current is called

Answer 44

electromagnetic induction

Question 45

What is a device that detects and measures very small electrical currents?

Answer 45

galvanometer

Question 46

To produce current, the lines of magnetic flux must be ....

Answer 46

cut

Question 47

What are the ways that the strength of magnetically induced current can be increased?

Answer 47

Strength of magnet( the more strength the better) Speed of the magnet ( the more speed the better) Number of coils ( the more the better)

Question 48

a devise that uses electromagnetic induction is a | The AC generator produces

Answer 48

generator | large amounts of electricity

Question 49

What can recharge the battery of an automobile?

Answer 49

alternators

Question 50

What generator uses a conducting fluid passing through a magnetic field at a high speed?

Answer 50

Magnetohydrodynamic generator

Question 51

When it is necessary to increase or decrease the voltage of an electric current— you can use a More - Less- SU- SD-

Answer 51

transformer Step-up step-down I= Less voltage more current; O= more voltage less current after I= more voltage less current; O= less current more voltage