The E layer is a region of the ionosphere, extending from about 90-150 kilometres above the Earth, which influences long-distance communications by strongly reflecting radio waves in the 1-3 megahertz. It is also called E region, Heaviside layer, or Kennelly-Heaviside layer. This region reflects radio waves of medium wavelength and allows their reception around the surface of the Earth. The …

Christian Johan Doppler (1803-1853) was an Australian scientist born in Salzburg who made and important discovery about the effects of sound and light when the sources are moving in relation to the observer. You may find the Doppler effect easier to understand if you consider what happens to the noise of a train as it approaches you and then fades …

The charging end of the glass furnace is commonly referred to as the ‘dog house’. It comprises a tank with spaced sidewalls. The glass batch (raw material) is fed continuously into this opening – called dog house – at one end of the tank, and the melted, refined and conditioned glass is drawn out the other end.

The human brain is at the top of the head, behind the forehead. The brains of other animals are behind their faces. Compared with the brain of an animal, the human brain has became enormous and room has had to be found somewhere for it. It is the size of our brain that more than anything else distinguishes us from …

Moong bean sprouts are the young shoots of moong beans used as a vegetable. Soybean is rich in oil and protein, as compared to moong bean sprouts.

Both creepers and climbers are weak-stemmed plants and, hence, cannot grow erect without support. The difference is that creepers spread horizontally along the soil. At the nodal regions – where leaves grow – they produce fibre-like roots arising from the base of the stem, which get fixed and grow further. Such stems in creepers are called prostrate stems. Climbers take …

Whenever it rains, the soil absorbs the water. The water goes down into the ground. When it reaches down to such as place where a porous rock or sand is surrounded by hard rocks, it is collected there. A pressure is built up due to hard rocks around it. When we dig a hole in the ground and it gives …

An Atom bomb releases energy generated by the breaking apart of plutonium or uranium nuclei. A hydrogen bomb release energy created when atoms of an isotope of hydrogen are brought together. It takes an atom bomb, to create the conditions to operate a hydrogen bomb so a fission device is installed to trigger a fusion, or thermonuclear, explosion, duplicating conditions …

The crocodiles, alligators, caimans and the gavial make up a group of about twenty reptiles. They all have the same basic appearance and, like the turtles and terrapins, they are all amphibious. The alligator differs from the crocodile in having shorter and broader snout although there is yet another, more definite difference. In both animals the fourth tooth of the …

Stars are hot bodies that give out light of their own, whereas planets shine only by reflecting light. Stars are composed of gas, but planets can be either gaseous or solid. The earth is a solid planet. Jupiter is a gaseous one. Nine planets orbit the Sun. In order of distance from the Sun, the are Mercury, Venus, Earth, Mars, …