These comprehensive RBSE Class 10 Science Notes Chapter 14 Sources of Energy will give a brief overview of all the concepts.
RBSE Class 10 Science Chapter 14 Notes Sources of Energy
→ Our energy requirements increase with our standard of living.
→ Energy can be obtained from various sources of energy. Although sun is the ultimate source of all energies.
→ Different sources of energy – There are various sources of energy e.g. air, water, coal, petroleum, natural gas, biogas etc. Although all these sources obtain energy from the sun.
→ Main sources of energy – (1) Coal (2) Petroleum and Natural Gas (3) Water (4) Nuclear (5) Wind.
→ Fossil Fuels-Fossil fuels are the natural fuels formed from the dead remains of the plants and animals which got buried deep under the earth millions of years ago, Coal, petroleum and natural gas are fossil fuels. They are non-renewable source of energy.
→ Thermal power plants – They generates electric power from heat energy which is produced by burning of fossil fuels.
→ Hydro-electric power plants – The electricity produced from the kinetic energy of the flowing water is called hydro-electric power and a plant which generates hydro-electric power is called hydro-electric power plant.
→ In order to fulfil our energy requirements, we try to improve the efficiency of energy usage and also try and exploit new sources of energy.
→ A good source of energy would be one –
- which would do a large amount of work per unit volume or mass
- be easily accessible
- be easy to store and transport
- be economical.
→ Improvement in the technology for using conventional source of energy –
(A) Biomass – It is the renewable source of energy.
Use of wood as fuel – Wood can be used directly or indirectly for obtaining heat energy.
Direct form – To obtain high amount of energy the direct use of it is not suitable to obtain heat energy.
Indirect form – When wood is burst in the absence of air, water and other volatile materials present in it get removed and a black coloured substance i.e. charcoal is obtained. It burns without smoke and produce more heat.
(B) Wind energy – Moving air is called wind. The energy possessed by moving air i.e. kinetic energy is called wind energy. Wind energy is an environment friendly and efficient source of renewable energy.
Wind mill – It is a device which converts the wind energy into mechanical or electrical energy.
Limitations of wind energy – The minimum wind speed is about 15 km/hr to maintain the required speed of the wind turbine. If it is not so, the generators stop working In Denmark maximum energy is generated using wind in the world. Because of this it is called the ‘Country of winds’.
→ We need to look for new sources of energy because the conventional source of energy like fossil fuels are in danger of getting exhausted soon.
→ Non-conventional or alternative sources of energy –
(A) Solar energy – The heat and light emitted by the sun is called solar energy. The daily average of solar energy obtained in any area of the earth is 4 to 7 kWh/m2. The amount of solar energy incident normally per second on 1 m2 area of the near. earth space at an average distance between the sun and the earth is called solar constant.
(B) Energy from the sea-(i) Tidal energy (ii) Wave energy (iii) Ocean thermal energy.
(C) Geothermal energy-The energy stored in the hot regions of earth’s crust is called geothermal energy.
(D) Nuclear energy-According to Einstein’s mass energy equation – E = mc2, the loss of mass of an atom converts into energy whereas c is the speed of light in vacuum = 3 × 108 m/s. This E is called nuclear energy.
→ The energy source we select would depend on factors like the ease and cost of extracting energy from the source, the efficiency of technology available for using that source of energy and the environmental impact of using that source.