Generating Electricity – Many types of problems are involved in generating of electricity. Some of them are described below:
- Hydroelectric power is one of the traditional methods of production of electricity. despite the fact that it is the cheapest way of getting electricity; some problems are three in this method. The people living in these areas where the dams are to be constructed are shifted to some other places. In winter, its capacity decreases due to shortage of water. Moreover, water table near a dam rises, due to which water logging occurs and the land becomes uncultivated.
- Electricity production by using thermal energy involves burning of fossil fuels (oil, gas, coal). These are non-renewable energy sources. That is why the existing reserves of fossil fuels are running short day by day and their prices are shooting up. Moreover, fossil fuels release smoke and other harmful gases in atmosphere.
- Many advanced countries use nuclear energy for production of electricity. Although it is not very expensive but sometimes it becomes very risky. The danger of harmful radiation leakage is always there. Another problem with this method is the proper disposal of waste material which is also highly radioactive.
- Solar power is becoming very popular these days. Solar energy is renewable source of energy and is available to everyone free of cost. Production of electricity by using solar energy is safe and causes no pollution, but still has certain problems. The major problem is the high initial cost of solar panels and storage batteries.
- Wind energy is also a renewable source of energy. It does not produce pollution the initial cost is very high. Moreover, wind farms cover large areas of expensive land and are very noisy.
We are living in an electronic age. Radio, television, computer, amplifiers, hi-fi sound system, worldwide communication system, mobile phones, artificial satellites etc., are common electronic system. They use electricity to perform their functions such as to presses input data and to obtain, alter, transmit or store information. All these functions are done by controlling the motion of electrons. The branch of physics that concerns with the behavior and control of motion of electrons is called electronics. Electronic systems use short pulses of electric current to carry information in the form of signals. Later on, thse signals can be changed into sounds, pictures or other information.
A well-known example of an electronic system is television. Without going through the details of internal working of its different parts, we can describe their functions by a block diagram of the system.
The following steps will explain how the system operates:
- A camera converts picture and a microphone converts sound into electronically signals at the TV station.
- These signals are mixed with carrier waves and are transmitted through transmitter antenna or cable.
- Signals are received by TV in the form of a weak alternating current.
- These signals are amplified by the amplifiers already installed in the TV.
- The circuits inside the TV separate video and audio signals.
- Video signals go to the picture tube that displays motion picture on the screen.
- Audio signals go to the speaker that converts them back into sound.