Sponge iron...

Sponge iron is a metallic product formed by the reduction of iron ore at a temperature just below the fusion point of iron. This product is called sponge iron due to its porous nature. It is also called as direct reduced iron (DRI).

Who built the Eiffel Tower in Paris?

The Eiffel Tower, an immense structure of exposed latticework supports made of iron, was erected for the Paris Exposition of 1889. The Prince of Wales officiated at the ceremonial opening. Of the 700 proposals submitted in a design competition, one was unanimously chosen, a radical creation of the French structural engineer Alexandre Gustave Eiffel. He was assisted by engineers Maurice Koechlin and Emile Nouguier, and architect Stephen Sauvestre.

Computer keep record of the time even when it is shut down...

Our computers are not run by a single operating system, but also the BIOS (basic input output system) which resides permanently in the chips of the motherboard to which virtually every computer hardware is connected. The BIOS is kept powered by a button cell (1.5 V approximately) or any variant. The cell remains present on the board and helps the BIOS remember not only the time but other hardware settings as well. The GUI (graphical user interface) syncs with the BIOS time every the computer is booted up and hence shows the computer shows the correct time.

About encoder and decoder.

An encoder is a device which transforms the data into some bits known only to it and the decoder is a device which transforms those coded bits to generate the original data again. These two are mainly used in computer technology but the underlying concept can be used anywhere. For example, the name ‘Delhi’ can be coded as ‘ihleD’ or ‘45#1278’. Later, the decoder regenerates the original ‘Delhi’ from this code as it knows the coding scheme.

... devised the sign language used by the hearing impaired.

Jerome Cardan devised the sign language. Deaf and mute people faced unreasonable brutality at one point of time. Jerome Cardan was an Italian doctor who believed that the mute and deaf people could be taught to communicate by using written characters. Finger characters were worked out for them in the seventeenth century which was very similar to the present-day finger alphabets. About seventy five years ago the deaf were taught to communicate ideas almost entirely by means of signs, facial expressions and finger alphabets.

Why is a tractor’s exhaust pipe bent upwards?

As the exhaust gases of an automobile are hot and tend to rise upwards, an upward bending pipe is the most natural shape. In a tractor, the driver’s seat is directly behind the engine and usually open. So, a backward-bending exhaust pipe will throw the exhaust gases directly at the driver. The rear part of a tractor is broader than its engine. Even a sideways-bent exhaust pipe will have the same effect. As a tractor has various agricultural attachments and a trailer, the exhaust pipe cannot be extended behind its rear tyres from below its chassis. A tractor works mainly on rough terrain which could damage an exhaust pipe protruding downward from the chassis.

Why are the people of Netherlands called the Dutch?

People from Holland are called Dutch by English-speaking people only. This word is the English counterpart of the Dutch words ‘diets’ and ‘duits’. ‘Duits’ means German since the Germans call themselves ‘Deutsche’. Around 1290 in the northern and eastern part of the Netherlands, the word was ‘duutsc’ and as the Frisian people (living in the North) spoke a language much more like English. The English adapted Dutch from Frisian Duutsc. Later, ‘duutsc’ became the Dutch word for their eastern neighbours Duits (German).

Why was Trafalgar Square built?

Trafalgar Square situated in London was built to memorialize Lord Horatio Nelson’s victory against Napoleon’s navy at the Battle of Trafalgar in 1805. The original name was to have been King William the Fourth’s Square, but George Ledwell Taylor suggested the name Trafalgar Square. A large monument to Lord Nelson, who won the battle of Trafalgar, stands in the center of the square. The four-sided base of Nelson’s column depicts Nelson’s naval victories. On the North — The Battle of the Nile; the East — The Bombardment of Copenhagen; the West — The Battle of St Vincent and the South — The Death of Nelson.

How is geothermal energy obtained?

Geothermal energy is contained in the intense heat that continually flows outward from deep within the earth. From the earth’s surface down through the crust, the normal temperature gradient (the increase of temperature with increase of depth) is 100 to 300 Celsius per kilometre. In certain areas, water seeping down through cracks and fissures in the crust comes in contact with this hot rock and is heated to high temperatures. Some of this heated water circulates back to the surface and appears as hot springs and geysers. However, the rising hot water may remain underground in areas of permeable hot rock, forming geothermal reservoirs. These, which may reach temperatures of more than 3,500 Celsius,can provide a powerful source of energy. Geothermal reservoirs within about 5 kms of the Earth’s surface can be reached by drilling a well. The hot water or steam from wells can be used to turn turbine generators to produce electricity. A power plant that uses this natural source of hot water or steam is called a geothermal power plant. Thus, in some cases, it is viable to capture geothermal energy and this renewable source of energy becomes obtainable.