Physics p2 - OCR Higher teir 0.0 / 5 ? PhysicsAll p2GCSEOCR Created by: LavleenGillCreated on: 16-04-17 15:18 5 things about renewable? Infinite amount. Never run out. Free. Solar - the sun must be out. Wind - It must be windy 1 of 23 How does solar panel/photocell? Silicon crystals absorb the energy from sunlight. Electrons are knocked Electrons move in one direction to produce a direct current. 2 of 23 Why is positioning and maintenance important? Maximum sunlight (south facing). Clean surface. Remove leaves/ branches etc. that would cast a shadow. 3 of 23 What does non renewable? Finite. Limit to the supply. 4 of 23 How does power stations work? Chemical/ nuclear energy used to heat and boil water. Steam turns the turbine. This turns a generator that transfers the energy to electrical energy. 5 of 23 How to increase efficiency of a power station? Use the heat from steam to heat homes. This will reduce the need to burn fossil fuels to heat the homes. 6 of 23 What are NEO actions? Constantly monitored by satellites, could be deflected by explosions. 7 of 23 How was the moon formed? Early Earth collided with Mars sized planet, molten Iron formed in Earth's core and debris formed into the Moon. 8 of 23 What are comets made from? Made of dust and frozen gas, speed up near the Sun. 9 of 23 What are asteroids? Made of rocks, asteroid belt is between Mars and Jupiter. 10 of 23 What was the Big Bang theory? + evidence Universe is expanding. Evidence ; the further away the galaxies move the more red the light is (red shift) and presence of CMBR. 11 of 23 How do AC generators? Coil of wire spinning in a magnetic field. Generating more electricity - More coils/ stronger magnet/ spin faster. 12 of 23 What are transformers? No energy loss. Induced current. Ratio of coils - step up voltage up, current down. Step down voltage down, current up. 13 of 23 What is the national grid? Network of electricity across UK. Voltage should be high so current is low. This reduces energy loss as heat. 14 of 23 How to calculate the power? P = current x voltage 15 of 23 What is off peak electricity? Can be used only at night which can be inconvenient. 16 of 23 How to calculate the cost for paying for electricity? P X T X COST PER KWH 17 of 23 What is the unit scaling for mega and kilo? Mega x 1000000 (6 0's), Kilo x 1000 18 of 23 What is Alpha radiation? Highly ionising, stopped by paper. Smoke alarm - smoke blocks the alpha. 19 of 23 What is beta radiation? Medium ionising, stopped by aluminium. Paper thickness - paper absorbs SOME beta. 20 of 23 What is gamma radiation? Low ionising, reduced by lead. Medical tracers - can get out of the body 21 of 23 What is nuclear waste? Stored in (steel) drums, sealed in glass and buried deep underground for a long time. 22 of 23 What is background radiation? Radiation all around us from cosmic rays, radon, gas and rocks. 23 of 23
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