switching dc power supplies

>The earth wire is much thicker in size and is made of copper. One end of it is connected to a copper plate buried deep under the earth. The earth connection is made to the electric meter and then to the main switch. In our homes, we receive supply of electric power th..

. But when sides of the coil interchange their positions, then the two commutator half rings R 1 and R 2 automatically change their contacts from one carbon brush to the other. Due to this change, the current keeps flowing in the same direction. Thus a DC generator supplies a cu..

Electric Generator (AC) - The electric generator converts mechanical energy into electrical energy. The two types of generators are DC and AC generators: DC Generators - A cycle dynamo and a car dynamo are examples of DC generators. They produce DC AC Generat..

Do we use dry cells for operating electrical appliance? It is not impossible to tap continuous supply of energy from electrochemical cells. Electrical circuits in homes, factories and offices receive such energy form local power companies. In most countries the energy is h..

Dams have been answer to huge and consistent supply of water and electric power needed for modern agriculture and urban cities. Large dams ensure the storage of adequate water, particularly during lean seasons and they also make available water supply to arid and sem..

Generally electrical appliances such as an electric bulb, geyser, heater, etc. are rated with power and voltage. If a bulb is rated 100W - 250V, it means that when a bulb is lit on a 250V supply, it consumes 100 W of electric power. This means that, 100 J of elec..

Question: An engine supplies 15,000 J of energy in one minute. Calculate the power of the engine Answer: Energy supplied by the engine =15000 J Time = 1 minute = 60 s Power of the engine = 250 watt..

I.Renewable: They can be replenished or reproduced easily. They are continually replaced at a faster rate than we use them up. Examples include solar energy, water power and biomass II.Non-renewable: They have a limited supply and can not be restored after use. Examples i..

Today most of our energy needs are supplied by the fossil fuels. In one hundred years coal will be the only one left as petroleum products may remain only for 3 to 4 decades. Little of stored energy will be left if we continue to use energy at the same rate. Fossil fuels are non-renewable..

Question: An electric motor of power 100 W is used to drive the stirrer in a water bath. If 50% of the energy supplied to the motor is spent in stirring the water, calculate the work done on the water in one minute. Answer: Power of the electric motor =100 ..