GCSE: Physics
I GOT ALL THIS INFORMATION OUT OF MY CLASSWORK BOOK AND NOTES. ITS NOT COMPLETE BUT WHEN I GET NOTES ON ELECTROMAGNETIC SPECTRUM I WILL UPDATE IT :D
chelly. xxxx
- Created by: Shola McGrory-Roberts
- Created on: 24-02-13 18:40
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- GCSE: Physics
- Generating electricity
- Sources of energy
- NON-RENEWABLE:coal, oil and gas
- RENEWABLE:hydro-electric, nuclear, wind
- Efficiency: fossil fuel power station approx. 40% efficient. Wind turbine is approx. 50% efficient
- Sources of energy
- Transmission of electricity
- Power stations generate around 30,000v
- it is then increased using a step up transformer to around 275,000v.
- carried around the national grid to supply demands, then reduced by step down transformer to around 230v (in britain)
- it is then increased using a step up transformer to around 275,000v.
- National gird! network of wires and cab els above and below ground connects to power stations ad homes
- power= voltage X current (w= v X a)
- E.G, find the power of an iron that has a current of 4A and voltage 230v . You should get 920v
- Power stations generate around 30,000v
- Energy supply and the home
- energy (j)= power (w) X time (s)
- cost= cost per unit x no of units
- energy (j)= power (w) X time (s)
- Energy Transfer
- conduction:mainly happens in solids because the particules are tightly packed. Particles get heated up and start to vibrate.
- good conductors: metal.
- convection: happens in liquids and gases. it needs the particles to move.
- Radiation: does not need particles for the heat to travel through.
- Black matt surfaces absorb & admit heat. Shiny white surfaces reflect and are poor absorbers and poor emitters,
- conduction:mainly happens in solids because the particules are tightly packed. Particles get heated up and start to vibrate.
- Waves and the electromagnetic spectrum
- waves: characteristics of waves. we have two types of waves: longitudinal and transversal
- longitudinal: need something to travel through. it compresses the particles. Sound is a an example.
- Transversal: dont need anything to travel through. light is an example.
- frequency measured in hz. amplitude. wavelengthmeasured in metres. wavespeed=frequencyx wavelength
- waves: characteristics of waves. we have two types of waves: longitudinal and transversal
- Generating electricity
- EDEXCEL
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