GENERAL KNOWLEDGE

Detailed explanation-1: -In 1892, Scottish scientist Sir James Dewar invented the vacuum flask. Through his work in cryogenics, he identified a need to keep a chemical placed in a flask at a stable temperature. To do this, Dewar placed a glass bottle in another larger glass bottle, and evacuated the air between the two bottle walls.

Detailed explanation-2: -The walls can be constructed from various materials, usually glass or stainless steel. The thermos bottle is a common example of a dewar. Many use a glass dewar that is protected by a metal or plastic exterior container. Examples of liquid nitrogen vessels; all are frequently referred to as “Dewars."

Detailed explanation-3: -The vacuum flask was designed and invented by Scottish scientist Sir James Dewar in 1892 as a result of his research in the field of cryogenics and is sometimes called a Dewar flask in his honour.

Detailed explanation-4: -Sir James Dewar was the inventor of the vacuum flask. He was professor of experimental philosophy at the University of Cambridge from 1875, and of chemistry at the Royal Institute in London. Among his other notable achievements was the liquefaction of hydrogen. He died in London on 27 March 1923.