How is geothermal energy used. Explain it in terms of modern world.
What is the temperature variation within earths crust. or Describe the temperature inside the earths crust.
Name two natural phenomenon through which geothermal energy can be obtained.
What is geothermal energy? Write its disadvantages.
How is tidal energy used ? or Describe usage of tidal energy in detail.
What is tidal energy? Why does tide occur in the sea or ocean.