P1 Energy and Electricity (1)

1. Convection is the transfer of heat energy in ________ and _______. This is because as they gain ________ particles move ________, spread out, become ________ density &. On cooling the particles l_______ energy, _______ down, get closer together, become _______ dense & _______. Draw an arrow on the diagram to show the convection current. Liquids rise Energy lose Faster slow Lower more gases falls Radiation Thermal ________ is the transfer of ________ energy. All objects _____ and absorb radiation. The ______ an object the more energy it radiates. Different materials transfer heat at different rates. ______ surfaces emit more thermal radiation than ______ surfaces. ______ surfaces are poor absorbers of radiation compared to ______ surfaces. black black emit heat white white hotter radiation The rate at which an object transfers energy depends upon 1.____________________________2.____________________________3. ____________________________ 4. ____________________________ What are the 3 methods by which heat can be transferred: ________ ________ ________ purple crystals Conduction transfers heat energy in solids. Thermal conductors are good at transferring heat e.g. ________________ ________________________________ Thermal insulators are materials through which heat is not easily transferred e.g. __ ________________________________because__________________________________________________________ heat P1 Energy and Electricity (1) What can be done to reduce heat loss in the home? _____________ ________________________________________________________________________________________________________ Name the non-renewable energy sources 1._______ 2. ______ 3. __________4. __________ What energy changes are shown in the pictures: ___________ ___________ ___________ ___________ ___________ ___________ Name the different forms of energy: _______________ _______________ _______________ _______________ _______________ _______________ _______________ Draw a sankey diagram to show the energy transfer in a 60J light bulb in which of 54 is wasted as heat: Efficiency= Useful Energy out Total energy in Calculate the efficiency of the light bulb (left). __________________________________________________________________________________________________________________________________________

2. power Rating (W) E= m x c x Θ J=kg x ‘C x J/kg ‘C Calculate the energy needed to heat up 2.5 kg water by 10 degrees. (Θ = 4200 J/kg ‘C) _________________________________________________________________________________________________________________________________________________________________ Total energy Transferred (J) When would insulation be called COST EFFECTIVE?____________ _________________________________________________________________________________ When would insulation be called EFFECTIVE?________________________________________________________________________ Define specific heat capacity ______________________________________________________________________________ time (s) x = What is the total energy in Joules used by 1.2kW microwave used for 5 minutes? ________________________________________________________________________________________________________________________________ Energy (kWh)= Power (kW) x time (h) If electricity cost 14p per kilowatt hour, how much will it cost to cut a large lawn that takes 3 hours using a 2000 watt lawn mower? ____________________________________________________________________ ____________________________________________________________________ The different energy resources have different advantages and disadvantages summarize some of these in the table: P1 Energy and Electricity (2) In the national grid what is the role of step up and step down transformer? Step up transformers ______________________________________________________________________________________________ Step down transformers ______________________________________________________________________________________________ What renewable energy resources are there? ________________________________________________________________________________________________________________________________________ What things do you need to consider when choosing an energy resource?__ _________________________________________________________________________________________________________ Fill in the boxes to show the energy changes that occur at each stage in a power station: boiler turbine generator transformer