Natrial Science Term 3 Circutz Flashcards
1
Q
In which direction does current flow
A
Current flows from positive to negative
This is the conventional direction of current flow.
2
Q
What is a complete circuit
A
A complete circuit is formed when wires connect the various components of a circuit without any gaps
3
Q
What does LED stand for?
A
Light emitting diode
4
Q
What is a gap in the circuit called
A
Break in the circuit
5
Q
Name seven components of a circuit
A
Battery, wire, lamp, buzzer, motor, switch, LED
6
Q
What is the symbol of a cell
A
- |I-
7
Q
What happens when a swich is turned off
A
It breaks the circuit and electricity can’t flow through
8
Q
What is an ammeter
A
It measures current
In amps
9
Q
How many cells are in a battery
A
At least 2
10
Q
What is current
A
The flow of electrical energy
11
Q
How is current measured
A
Using an ammeter
12
Q
What is current measured in
A
Amps
13
Q
In how many places is a ammeter connected to the circuit
A
1
14
Q
What is voltage
A
The pressure from the power source to push the current around the circuit
15
Q
What is voltage measured with
A
A voltmeter
16
Q
What is voltage measured in
A
Volts
17
Q
In how many places is a voltmeter connected to the circuit
A
2
18
Q
What is voltage known as
A
Electrical potential difference
19
Q
What is a simple circuit
A
A compleat path that electrical current can travel through
20
Q
What is a series circuit
A
An electrical path that is arranged in a series
21
Q
What is a parallel circuit
A
A closed circuit that has more than one path
22
Q
What are the parts of a light bulb
Name 5
A
Glass, gas, lead, filament, base.
23
Q
What does a cell/ battery do
A
Provides electrical energy
24
Q
What does a power supply do
A
It is alternative to using cells
25
What does wire do
Allows current to travel
26
What does a bulb/ light/ lamp do
Converts electrical energy into heat and light
27
What does a motor do
Converts electrical energy into movement energy
28
What does a buzzer do
Converts electrical energy into sound energy
29
What does a switch do
Allows circuits to be opened or closed
30
Name 3 components of a series circuit
1. Only one pathway for current to follow
2. Light bulbs connected in a row
3. If one light bulb breaks no other light bulbs will work 💡
31
Name 3 components of a parallel circuit
1. More than one pathway for current to follow.
2. Lightbulbs are connected below each other
3. If one light bulb breaks the other light will still work
32
If a lightbulb is missing or broken in a parallel circuit will the other bulb light? explain.
Yes, there is still a pass for the current to travel through
33
If a lightbulb is missing or broken in a series circuit, will the other bulb light? explain.
No, there is a break in the circuit
34
In a circuit, what is the flow of electrical energy called
Current
35
Electrons flow in One Direction in a circus and current flows in the opposite electrons flow from? And current flows from?
Electrons: negative to positive
Current: positive to negative
36
What do we call it when a light bulb is lit
A fixed or complete circuit
37
What do we call it win a lightbulb is unable to light up and there is a gap in the circuit
A open or incomplete circuit
38
What is a gap in the circuit called?
Break in the circuit
39
What is a component called that we used to create a gap in the circuit?
A Switch
40
The power source in a circuit is called a what
Battery?
41
What is the battery made of?
Two or more cells
42
You have these parts does a circuit need to work properly
A. Battery. B. Bulb. C. Paper clip
A
43
What do batteries do in a circuit?
They provide electrical energy
44
What is a battery?
2 or more cells that are connected
45
When is switch is in the on position that means that . . .
Electricity can flow through the swich
46
Name 10 insulators
Paper, fabric, glass, wood, leather, rubber, ceramic, cardboard, plastic and chalk.
47
Name a conductor
Metal
48
Name 4 metals that are conductors and list their property’s
Copper: common material used for wiring
Silver: best conductors. Very expensive, so rarely used for wiring.
Gold: does not rust, is expensive and is only used used when high quality contacts are needed
Aluminium: not very good conductor but is used where weight is a consideration. It is not as heavy as copper.v
49
What is the purpose of an insulator
To prevent electricity from traveling down the wrong paths / to keep the electricity from traveling to the wrong spots
50
Why don’t birds get shocked when they sit on power lines
The bird isn’t sitting and touching the ground
The wires could be insulated with plastic
51
What is in a battery
Chemical energy
52
What is the main resource of electrical energy in South Africa
Coal
53
Name the process in which fossil fuels are made
1. Millions of years ago in a low lying wetland areas, huge ferns and forests grew. They absorbed energy from the sun.
2. Over time these plants died and formed in to layers of rotting materials. Over time pressure from above packed these layers together to form peat
3. When sand and water collected on these layers, they were pressed together even more tightly and this made a soft brown layer called lignite
4. As more sand and mud piled on top more pressure occurred the heat inside the earth helped to slowly turn the lignite in the earth crust into black coal
54
Explain the process of coal being transformed into electricity.
1. Coal is transported from a storage area to the boiler
2. Coal burns and heats water in boiler.
3. Hot water turned into steam.
4. Steam is used to turn a turbine. A Turbine is like a huge wheel with blades.
5. The moving turbine of the generator produces electricity. A generator is a machine that changes the energy of the moving turbine into electrical energy.
6. The electricity travels along power the power lines over long distances
7. The electricity carried by the power lines has a lot of energy and it is dangerous. Transformers at sub- stations reduce the amount of energy carried by electricity before it enters our homes.
8. People use electricity when they switch on lights or use electrical appliances.
6.
55
What does infrastructure mean
The structures and other things that are needed to make sure something works properly.
56
Name a few infrastructures needed to produce electricity.
Coal mine, transport, a coal-burning power station, substations, pylons and power cables, transformers.
57
What does each electrical appliance need
A wattage rating
58
What is wattage
The amount of electrical power an appliance requires to work.
59
What is power measured in?
Units called watts ( W )
60
What does electrical usage depend on.
How long the electrical appliance is used for.
61
What is the main resource used to generate electricity in South Africa
Coal
62
Which appliances use the most electricity
Heating
63
How much electricity does an iron approximately use
Approximately 1000 watts an hour
64
How much coal and water does Eskom use for 1 unit of electricity
A little more than half a Kilogram of coal
🌊: nearly 1 and a half Liters of water
65
What how much waste does it create to make 1 unit of electricity
155g of ash
1kg carbon dioxide
66
What can the ash and carbon dioxide cause
illness such as bronchitis and asthma
67
What does renewable mean
That it can can be reused
68
What chemical is used to make nuclear energy
Uranium
69
Name a few types of renewable energy
Solar, wind, hydropower, biomass and geothermal
70
What do solar panels contain
Photovoltaic cells
71
What do photovoltaic cells do
Convert cells into electrical energy
72
What do photovoltaic cells do
Convert cells into electrical energy
73
Name a few non renewable energy’s
Fossil fuel oil, natural gas, coal, nuclear
74
Name 2 types of illegal connections
1. Running your own cables from the homes of other people to power your house
2. People connect wires to the electricity poles to steal electricity because they don’t want to pay for it.
75
Are illegal connections safe and allowed
No, they are both unsafe and against the law,
76
Where does renewable energy come from
Natural resources and are naturally replenished. Examples of these are: wind and waves
77
Where does solar energy come from
The sun
78
What can the sun be used for
Heat energy
79
What are solar panels used for
Converting sunlight into electrical energy
80
What are wind turbines used for
Converting wind energy into electricity
81
How does a wind turbine convert wind energy into electricity
The wind blows the blades around and this movement is converted into electricity
82
What is a group of wind turbines called
A wind farm
83
What is hydropower
The energy that comes from flowing water
84
How do hydropower plants work
Water that flows down a fast flowing river is used to the spin turbines that generate electricity
85
Apart from fast flowing rivers how can you generate electricity whit water
The movement of big waves at sea can also be used to generate electricity
86
What is geothermal energy
The energy generated and stored in the earth
87
Why don’t we use renewable energy all the time
1. Renewable energy such as wind or sunshine can’t be stored to be used when we need it
2. If the wind doesn’t blow, or if it isn’t very sunny, then there may not be enough power for everyone
3. Non renewable resources such as oil or coal can be stored and used when they are needed
4. Non renewable energy is usually cheaper than renewable energy, which means not everyone can afford to use renewable energy
88
Is it always warm underground
Yes, even if it is cold on the surface
89
What do we use the heat from underground to do
Heat our houses
90
What shows us how hot it is underground
The lava from volcanos
91
What is biomass and. How can it be obtained
Biomass means natural material. Energy can be obtained by natural waste materials such as scrap pieces of wood, dead trees and unused parts of crops.
92
What does a cow give that you can burn for energy
Gas 🐄💨
93
How do we get energy produced by coal
Coal is mined from under ground and burned in large power stations to produce electricity
94
Can the coal that we use be replaced
No, the coal that we use cannot be replaced so one day we will have no coal left
95
Is burning coal bad for the environment? Why
Yes, lots of carbon dioxide gets released into the atmosphere
96
Where is oil found and how do we get it to surface
Deep under the surface
People then pump it to the surface for us to use
97
What is oil used for
It is burned for electricity
It can also be used as fuel for our cars
98
Can we replenish oil
No
If we keep using the oil eventually there will be no more oil left
99
What do nuclear power stations use as fuel to make electricity
Uranium
100
Is Uranium renewable. Explain your answer
No, it is a natural resource taken from the ground so it is now renewable
101
Is nuclear power a clean way of generating electricity
Yes, it doesn’t produce much waste
102
Where do we find natural gas
Deep underground
103
What do we do with the natural gas we find deep underground
We pump it into our homes
104
What do we use natural gas for
Cooking
We burn it in a boiler to heat our water
105
Will the natural gas we pumped from underground run out
Yes,
It is a non renewable resource
106
Name a other way to measure to measure volts other than using an voltmeter
There is no other way 😃 .
107
Name a other way to measure to measure volts other than using an voltmeter
There is no other way 😃 .
