Which of the following is a non-renewable source of energy?
  • Wood
  • Sun
  • Fossil fuels
  • Wind
Acid rain happens because
  • Sun heats up the upper layer of the atmosphere
  • burning of fossil fuels releases oxides of carbon, nitrogen and sulphur in the atmosphere
  • electrical charges are produced due to friction amongst clouds
  • earth atmosphere contains acids
Fuel used in thermal power plants is
  • water
  • uranium
  • biomass
  • fossil fuels
In a hydro power plant
  • potential energy possessed by stored water is converted into electricity
  • kinetic energy possessed by stored water is converted into potential energy
  • electricity is extracted from water
  • water is converted into steam to produce electricity
Which is the ultimate source of energy?
  • Water
  • Sun
  • Uranium
  • Fossil fuels
Which one of the following forms of energy leads to least environmental pollution in the process of its harnessing and utilisation?
  • Nuclear energy
  • Thermal energy
  • Solar energy
  • Geothermal energy
Ocean thermal energy is due to
  • energy stored by waves in the ocean
  • temperature difference at different levels in the ocean
  • pressure difference at different levels in the ocean
  • tides arising out in the ocean
The major problem in harnessing nuclear energy is how to
  • split nuclei
  • sustain the reaction
  • dispose off spent fuel safely
  • convert nuclear energy into electrical energy
Which part of the solar cooker is responsible for greenhouse effect?
  • Coating with black colour inside the box
  • Mirror
  • Glass sheet
  • Outer cover of the solar cooker
The main constituent of biogas is
  • methane
  • carbon dioxide
  • hydrogen
  • hydrogen sulphide
The power generated in a windmill
  • is more in rainy season since damp air would mean more air mass hitting the blades
  • depends on the height of the tower
  • depends on wind velocity
  • can be increased by planting tall trees close to the tower
Choose the correct statement.
  • Sun is considered as an inexhaustible source of energy
  • There is infinite storage of fossil fuel inside the Earth
  • Hydro and wind energy plants are non polluting sources of energy
  • Waste from a nuclear power plant can be easily disposed off
In a hydroelectric power plant more electrical power can be generated if water falls from a greater height because
  • its temperature increases
  • larger amount of potential energy is converted into kinetic energy
  • the electricity content of water increases with height
  • more water molecules dissociate into ions
Choose the incorrect statement regarding wind power.
  • It is expected to harness wind power to minimum in open space.
  • The potential energy content of wind blowing at high altitudes is the source of wind power.
  • Wind hitting the blades of a windmill causes them to rotate. The rotation thus achieved can be utilised further.
  • One possible method of utilising the energy of rotational motion of the blades of a windmill is to run the turbine of an electric generator.
Choose the incorrect statement.
  • We are encouraged to plant more trees so as to ensure clean environment and also provide biomass fuel.
  • Gobar gas is produced when crops, vegetable wastes, etc. , decompose in the absence of oxygen.
  • The main ingredient of biogas is ethane and it gives a lot of smoke and also produces a lot of residual ash.
  • Biomass is a renewable source of energy.
what is true about hydroelectric power plants?
  • water is converted into steam and the it is used to rotate turbine
  • it uses fossils fuels to generate electricity
  • The potential energy of the water is converted into kinetic energy of water and which is then used to rotate turbine to generate electricity
  • None of these
what are the drawback of solar energy heating devices?
  • It can not be used in night
  • it can not be used if the sky is covered with clouds
  • the direction has to be changed after short interval in order to have devices always facing sun
  • All the above
which gas is not present in Bio-gas?
  • Methane
  • Carbon dioxide
  • Hydrogen sulphide
  • Nitrogen
The power generated in a windmill?
  • Depends on the height of the tower.
  • Depends on wind velocity
  • Can be increased by planting tall trees close to the tower
  • none of these
which of these is true for solar energy?
  • The energy obtained from sun is called solar energy
  • Ultra violet rays are completely absorbed and eliminated by the atmosphere
  • it is a renewable source of energy
  • All the above
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