GENERAL KNOWLEDGE

Detailed explanation-1: -The earliest version of the CRT was known as the “Braun tube", invented by the German physicist Ferdinand Braun in 1897. It was a cold-cathode diode, a modification of the Crookes tube with a phosphor-coated screen. Braun was the first to conceive the use of a CRT as a display device.

Detailed explanation-2: -Braun’s invention of the cathode-ray tube, also known as the Braun’s tube, in 1897 built on the research done by fellow German physicist Heinrich Geissler and British chemist William Crookes. In order to study high-frequency, alternating-current electricity, Braun came up with the tube that now bears his name.

Detailed explanation-3: -Johann Hittorf discovered cathode rays in the year 1869. He used Crookes tubes to observe shadows cast on the glowing wall opposite the tube’s negative electrode.