10th Class

       Tidal Energy   Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power. The first large-scale tidal power plant started operation in 1966. Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power. Among sources of renewable energy, tidal power has traditionally suffered from relatively high cost and limited availability of sites with sufficiently high tidal ranges or flow velocities, thus constricting its total availability. Tidal power is extracted from the Earth's oceanic tides; tidal forces are periodic variations in gravitational attraction exerted; by celestial bodies. These forces create corresponding motions or currents in the world's oceans. The magnitude and character of this motion reflects the changing positions of the Moon and Sun relative more...

       Solar Power Plant   Solar power is the conversion of sunlight into electricity, either directly using photovoltaic’s (PV), or indirectly using concentrated solar power (CSP) or to split water and create hydrogen fuel using techniques of artificial photosynthesis. Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a heat source for a conventional power plant. A wide range of concentrating technologies exists. The most developed are the parabolic trough, the concentrating linear fresnel reflector, the Stirling dish and the solar power tower. Various techniques are used to track the Sun and focus light. In all of these systems a more...

       Biogas Plant   Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Biogas originates from biogenic material and is a type of biofuel. Biogas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material and -more problematic- energy crops. Biogas comprises primarily methane and carbon dioxide and may have small amounts of hydrogen sulphide, moisture and siloxanes.   The gases methane, hydrogen and carbon monoxide can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel. Biogas can be used as a fuel in any country for any heating purpose, such as cooking. It can also be used in anaerobic digesters, where it is typically more...

       Hydroelectric Power Plant   Hydroelectric power plant is the power plant in which electrical energy is produced using the kinetic energy of the water. Hydroelectricity is also the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy. Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. The power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This method produces electricity to supply high peak demands, by moving water between reservoirs, at different elevations. At times of low electrical demand, excess generation capacity is used to pump water into the higher reservoir. When there is higher demand, more...

       Thermal Power Plant   The power plant in which the electricity is produced by burning of coal is called thermal power plant. A thermal power station is a power plant in which the prime mover is steam _ driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated. This is known as a Rankine cycle. The greatest variation in the design of thermal power stations is due to the different fuel sources. The energy efficiency of a conventional thermal power station, considered as salable energy as a percent of the heating value of the fuel consumed, is typically 33% to 48%. This efficiency is limited as all heat engines are governed by the laws of more...

       Fuel   Fuel are those materials which produce heat energy on burning. For example, the fuel like wood, LPG, coal, petrol, diesel, etc produces heat energy while they burn. All fuels produce heat energy, on burning, in different amounts. It depends on the calorific value of the fuel. The calorific value of the fuel is defined as the amount of heat produced by burning of a unit mass of fuel. For example the calorific value of the fuel is 33000 j/g. Hydrogen has highest calorific value of 150 kj/g and hence it can be the best sources of the fuel. H Most of the fuel which contains hydrogen and carbon has high calorific value than others. Before a fuel catch fire and starts burning it must be heated to a certain minimum temperature. The minimum temperature to which a fuel must be more...

         Introduction   We use different sources of energy in different forms. Without energy all our activities will come to stop and we will not be able to survive. For doing work we need energy. For this we need a source of energy which would provide us adequate amount of energy in a convenient form for a long period of time. All the source of energy can be divided into categories, i.e. renewable and non-renewable sources of energy.           Forms of Energy              Renewable Sources of Energy Those sources of energy which can be replenished in short time in nature and are inexhaustible, are called renewable sources of energy. For example, tree, the wood obtained from trees are renewable sources of energy. If more...

        Domestic Circuit   We receives electric supply in our home from the main power supply through cables or poles. It consists of two wires, one with red insulation called live wire and other with black insulation called neutral wire. The potential difference between two wires is 220 volt. These two wires are connected into our homes via meter board through main switch, which consists of safety devices called fuse. From there it is connected to the different switch through the wiring in our house, which are connected in parallel. Often we use two different circuit one with 15 A current used for appliances with higher power rating such as air coolers, geysers etc and other circuit is of 5 A current rating for bulbs, fans, TV etc. There is a third wire with green insulation called earthing and is usually connected to more...

         Electric Generator   Electric generator is a device which convert mechanical energy into electrical energy. A small generator is called a dynamo which is used in bicycle. It works on the principle of application of electromagnetic induction.-When a straight conductor is moved in a magnetic field, the current is induced in the conductor. It is of two types: alternating current generator and direct current generator. An A.C. generator produces current which reverses its direction continuously after every half cycle. A simple A.C. generator consists of a rectangular coil PQRS which can be rotated rapidly between the poles of the horseshoe magnet as shown in the figure given below. The coil is made up of large number of turns of insulated copper wire. The two ends P and S of the coil are connected more...

       Electromagnetic Induction   This concept was first introduced by Michael Faraday in 1831 when he discovered that magnet can be used to produced electric current. The production of electricity from magnetism is called electromagnetic induction. This can be demonstrated by moving the conducting wire between the poles of the magnet or by moving the magnet, or by keeping the conductor fixed and moving the magnet. A galvanometer is an instrument which can detect the presence of feeble current in the circuit. Take a galvanometer and connect in series with the circuit of the conducting wire and place it between the poles of the magnet. When the wire is stationary, no deflection in the galvanometer can be seen and as we move the wire between the poles of the magnet we see the deflection in the galvanometer.   more...