Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
61 Cards in this Set
- Front
- Back
As the frequency of a note increase, what happens to it's pitch ? |
It increases as well |
|
What does the loudness of a note depend on ? |
It depends upon the amplitude of the sound wave |
|
What fuel is used in a nuclear power station ? |
Uranium or plutonium |
|
Describe briefly, how do electrical generators are driven to produce electricity in a power station driven by turbines
(use the words: water, steam, turbine) |
Water is heated to produce steam. This steam drives a turbine, which is coupled to an electrical generator that produces electricity |
|
What are the 3 sources for fuel in a fossil-fuel power station ? |
-Coal -Oil -Natural gas |
|
True or false, uranium is burned to produce energy |
False, uranium atoms do not burn; they perform nuclear fission |
|
Where can a bio fuel be obtained from? |
Living, or recently living organisms |
|
Are bio fuels a renewable energy source ? |
Yes, they are renewable
|
|
What does solar energy travel from the sun to the Earth as ? |
Electromagnetic radiation
|
|
What can we use to convert solar energy into electrical energy ? |
Solar cells |
|
Where does geothermal energy come from ? |
It comes from inside the Earth by radioactive processes |
|
The greater the temperature difference between an object and its surroundings, the greater the..? |
The greater the rate at which energy is transferred |
|
Name two things that the rate at which energy is transferred depends on |
-Materials that the object is in contact with
-The object's shape -The object's surface area |
|
If we wanted to maximise the rate of energy transfer, what could we do ? |
-Use good conductors -Make sure the objects are painted in dull black -Have an air flow around the object maximised |
|
If we wanted to minimise the rate of energy transfer, what could we do ? |
-Use good insulators -Objects are painted in white and are shiny -Prevent convection currents by trapping air in small pockets |
|
In a vacuum flask, what does the vacuum inside it prevent? |
It prevents: conduction and convection
|
|
Define the refraction of light |
The refraction of light is the change of direction of a light ray when it crosses a boundary between two transparent substances |
|
What happens to the wavelength and frequency of a wave as it crosses a boundary ? |
The wavelength changes, but the frequency stays the same
|
|
What colour light is refracted the most ; Red, blue, violet or green ? |
Violet is refracted the most, red is refracted the least |
|
Define base load demand |
A constant amount of electricity is provided by nuclear, coal-fired and oil-fired power stations |
|
Order these types of power stations from quickest to slowest start-up time : gas-fired, coal-fired and nuclear |
Fastest - Gas, coal then nuclear |
|
What materials are the best conductors ? |
Metals |
|
What state of matter does conduction mainly occur in ? |
Solids
|
|
What kind of energy occurs in order for particles to past energy from one end of the solid, to the other end ? |
Kinetic energy |
|
Why are non-metals poor conductors ? |
They don't contain free electrons meaning energy can't be passed on as easily |
|
Define power |
Power is the rate of transfer of energy |
|
What is the unit for power ? |
It is a watt, W |
|
How many watts is in 2.5kW ? |
2500 watts |
|
What is diffraction ? |
It is the spreading out of waves when they pass through a gap or round the edge of an obstacle |
|
What can happen to the reception of radio waves on the top of a hill if they don't refract enough ? |
The radio and TV reception will be poor |
|
True or false, it is possible to destroy energy, but we cant create it |
False, we cannot create or destroy energy |
|
Name 5 different forms of energy ? |
-Light -Sound -Kinetic (movement) -Nuclear -Electrical -Gravitational potential -Elastic potential -Chemical |
|
Yes or no, do all objects emit infra-red radiation ? |
Yes, they do |
|
If a object is hotter, will more or less infra-red radiation be given off ? |
More radiation will be given off |
|
Can infra-red radiation travel through a vacuum ? Give an example |
Yes it can. This is how we get energy from the sun |
|
What are the 3 states of matter ? |
Solid, liquid and gas |
|
In a liquid, describe the arrangement of particles |
Particles are in contact with each other but can move about freely and at random. This is why a liquid doesn't have a fixed shape and can flow |
|
Which of these two's particles move at random faster ? Gas or liquid |
Gas |
|
In what state of matter does convection occur ?
|
Fluids, so liquids or gases |
|
Define convection |
Convection is the circulation of a fluid causes by heating it |
|
How do we increase the rate of evaporation ? |
-Increase the surface area the liquid -Increase the temperature of the liquid -Create a draught of air across the liquid's surface |
|
How can we decrease the speed of condensation ?
|
-Decrease the surface area -Increase the surface temperature |
|
What is energy measured in ? |
Joules (J) |
|
True or false, a machine can be more than 100% efficient |
False |
|
How can you make a machine more efficient ? |
Reduce the : friction, air resistance, electrical resistance and noise due to vibrations |
|
Does efficiency have a ration ? Explain why |
No it doesn't. This is because it is a ratio. |
|
An electrical motor transfers 48kJ of electrical energy into kinetic energy in 2 minute. What is the useful power output of the motor ? A-400 B-40 C-240 |
A- 400 48,000J / 120 seconds = 400W |
|
How could you reduce your home energy bills ? Name 2 ways (hint-think about the roof, windows, appliances) |
-Buy newer, and more efficient appliance -Buy loft insulation to stop air escaping through roof -Ensure that the windows are double, or triple glazing |
|
How much electrical energy is transferred when a 9kW shower is used for 15mins ? |
2.25kw/h 9 x .25 = 2.25 |
|
What is tidal power ? |
Tidal power is a form of hydropower that converts the energy obtained from tides into useful forms of power, mainly electricity |
|
How does tidal power work ? |
Water is trapped behind a barrage, then let back through the barrage and the water turns turbines and energy is produced |
|
What are 2 advantages of using nuclear energy ? |
-No production of pollution gases -Reliable |
|
By using some renewable energy resources, what can be affected ? |
Plant and animal life can be affected |
|
What is the mains voltage in homes and offices ? |
It is 230V |
|
What is a longitudinal wave made up of ? |
Compressions and rarefactions |
|
Name all waves on the electromagnetic spectrum |
-Radiowaves
-Microwaves -Infra-red radiation -Visible light -Ultraviolet -X-rays -Gamma rays |
|
What is the longest wave on the electromagnetic spectrum ?
|
Radiowave |
|
Define the doopler effect |
A change in the frequency of a wave, either sound or light, occurring when the source is in motion, with the frequency increasing when the source approach the object and decreasing when they move apart. |
|
What provides evidence that the galaxy is moving away from us ? Red-shift or blue-shift |
Red-shift |
|
If we looked a galaxy and saw a blue-shirt in light, would it be getting closer or further away from Earth ? |
It would be getting closer |
|
The further a galaxy is from us, the bigger or smaller the red-shift? |
Bigger red-shift |