Electroencephalography or EEG is the technique of capturing brain’s electrical activity. It was first discovered by Hans Berger in 1929. EEG signal recording can be done using scalp electrodes or intracranial procedure of capturing EEG. International 10-20 system of electrode placement is widely used across the globe for recording scalp EEG. Neurologist classified the brain … Read more
Air Pollution The air pollution is defined as an imbalance in quantity of air which adversely affects the biotic community. In other words, the contamination of undesirable air pollutant which adversely affects environment because of lowering quality of air. Air pollution comes from a wide variety of sources. Some of the most excessive sources include … Read more
Solar Radiation data are measured by 3 devices i.e. Pyranometer Pyrheliometer Sunshine Recorder 1. Pyranometer It is an instrument which is designed to measure Global radiation. It can be placed on horizontal as well as on the inclined surface. If Pyranometer is shaded by a shading ring, it measures the diffused radiation. Shading ring prevents the … Read more
Global Warming The term ‘Global Warming’ was given by Wally Broecker. Global warming is a phenomenon which refers increase in average temperature of the atmosphere of the earth over a long period of time. Before the pre-industrial revolution, the average atmospheric temperature of the earth was 15°C. Currently it is 16.6°C. In last 100 years … Read more
Due to the frequent increase in electricity tariff charged by the electric utility, poor reliability of electric supply, forced outages, long power cuts, etc., a large number of industries have switched over to their own generating station (plant) within their own campus. This method of generation is called Captive Power Generation and such plants are … Read more
Definition of Pollution Pollution can be defined as an undesirable change in the chemical, physical or biological characteristics of air, soil, water and other physical domains that may harmfully affect the life or create a potential health hazard of any living organism. It can occur naturally, for example through volcanic eruptions, or as the result of … Read more
Q. For what purpose metallic sheath is provided in underground cables? Ans. The metallic sheath is provided around the insulation to protect it against ingress of moisture, gas or other damaging liquids (acid or alkalies) from the soil and atmosphere. Q. Why is a layer of bedding provided over the metallic sheath in underground cables? … Read more
A voltage telemetry system transmits the measured variable as a function of AC or DC voltage. A slide wire potentiometer is connected in series with the battery. The signal transmitting medium is essentially a copper wireline. A voltage telemetry system is shown in Fig. 1. The sliding contact is positioned by a pressure sensitive, … Read more
Amplification It is an operation of an amplifier intended to make a signal stronger by increasing the power of a signal. The amplifier output matches the input signal shape but with a larger amplitude. It may be Linear or nonlinear. Companding It is a technique for compressing and then expanding (or decomposing) an analog or … Read more
Q. On what factors does the power output of a hydropower plant depend? Ans. The power developed by a hydro plant depends upon the discharge and head and is directly proportional to their (discharge and head) product. Q. What is meant by catchment area? Ans. The catchment area is the area, bounded by water sheds, … Read more