Doc Brown's GCSE OCR Gateway Science-Physics Revision Notes

OCR GCSE Gateway Science Physics Module P2 Living For The Future (Energy Resources)

Unit-Items P2a Collecting energy from the Sun

  1. Appreciate that the Sun has supplied our planet with energy for a long time.

  2. In this unit you study how solar energy can be used, in a sustainable way, to provide us with some of our energy needs.

  3. Some of your research, practical investigations etc. may have included:

    • a) how the voltage and current from a photocell varies with distance from the light source,

    • b) how the power of a photocell depends on its surface area and its distance from the light source,

    • c) how photocells can be connected to increase their voltage,

    • d) the use of photocells in remote locations,

    • e) building a simple solar collector eg from aluminium foil and an umbrella,

    • f) building a model greenhouse,

    • g) the use of passive solar heating of buildings,

    • h) the use and distribution of wind turbines in the UK,

    • i) to what extent solar energy can help ensure the UKís future energy security.

  4. Know that photocells:

    • a) transfer light into electricity,

    • b) produce direct current (DC),

    • c) can operate in remote locations,

    • d) have a power or current that depends on the surface area exposed to sunlight.

  5. Know that DC electricity is current in the same direction all the time.

  6. Be able to describe how the Sunís energy can be harnessed:

    • a) radiation from the Sun can be absorbed by a surface and transferred into heat energy,

    • b) produces convection currents (wind) to drive turbines,

    • c) how glass can be used to provide passive solar heating for buildings,

    • d) light can be reflected to a focus by a curved mirror.

  7. Be able to describe some advantages and disadvantages of using photocells to provide electricity:

    • a) low maintenance,

    • b) no need for power cables,

    • c) no need for fuel,

    • d) long life,

    • e) renewable energy resource,

    • f) no polluting waste,

    • g) no power at night or in bad weather.

  8. HT only: Be able to describe how light produces electricity in a photocell:

    • a) energy absorbed by photocell,

    • b) electrons are knocked loose from the silicon atoms in the crystal,

    • c) electrons flow freely.

  9. HT only: Be able to understand how the current and power produced in a photocell depends on:

    • a) light intensity

    • b) surface area exposed

    • c) distance from the light source.

  10. Be able to describe the advantages and disadvantages of wind turbines:

    • a) renewable,

    • b) no polluting waste,

    • c) visual pollution,

    • d) dependency on wind speed,

    • e) appropriate space and position needed.

  11. Be able to explain why passive solar heating works:

    • a) glass is transparent to Sunís radiation,

    • b) heated surfaces emit infrared radiation of longer wavelength,

    • e) glass reflects this longer wavelength infrared.

  12. HT only: Know and understand that an efficient solar collector must track the position of the Sun in the sky.