AC DC CHAP 1

• Energy is the fundamental need of our everyday life. So much so, that the quality of life and even its sustenance, is dependent on the availability of energy
• It is imperative for us to have a conceptual understanding of the various sources of energy, the conversion of energy from one form to another and the implications of these conversions
• Energy conversion from one form to another is a well-known phenomenon
• The Law of Conservation of Energy tells us that the only thing that takes place with energy is the transformation from one form to another
• Energy Conversion


  The process where there is a change in energy from one form to another such as the conversion of nuclear energy into heat energy, the conversion of light energy into heat, thermal energy into work etc.
• Forms of Energy


  • Radiation energy
  • Chemical energy
  • Potential energy
  • Kinetic energy
  • Thermal energy or heat
  • Mechanical energy, or rotational energy, also called shaft power
  • Electrical energy
• Energy Sources


  • Biomass
  • Solar radiation, i.e., energy from the sun
  • Hydro resources, i.e., energy from water reservoirs and streams
  • Wind energy, i.e. energy from wind
  • Fossil fuels, like coal, oil and natural gas
  • Geothermal energy, that is, the energy contained in the form of heat in the earth
• The Use of Fire

  1. Burning dried plant, wood, and animal waste and used the resultant energy for cooking and heating

  2. Use of mechanical energy to harness the energy of flowing water and wind
• Waterwheels


  • Used to grind grain, drive sawmills and pumps, drive tilt hammers for forging iron
• Windmills


  • Used to convert the wind energy into mechanical energy for grinding grain, pumping water, and draining the lowland areas
• Steam Engine


  Developed as the first device for converting thermal energy into mechanical energy to meet the demands of the industry
• Newcomen Engine


  • Converted only about one percent of the thermal energy in the steam to mechanical energy, but remained unrivaled for more than 50 years
• Watt's Engine


  • Added a separate condenser to make it unnecessary to heat and cool the cylinder with each stroke, reducing fuel costs by about 75 percent
• The Conservation of energy is the principle that energy can neither be created nor destroyed. It can only be converted from one form to another or transferred from one object to another
• The energy transformation is applicable to all types of energy such as kinetic energy, potential energy, light energy, heat energy, sound energy, nuclear energy, gravitational potential energy etc.
• These transformations would occur again and again till the time that resource is present there
• The friction effect and the air-pressure are the other factors which can affect the transformation to some extent