GENERAL KNOWLEDGE

Detailed explanation-1: -And in 1923, according to several sources, an early transatlantic transmission of a human voice, sent point-to-point, was sent between Manchester, England and Pittsburgh, Pennsylvania in the US.

Detailed explanation-2: -On December 12, 1901, Marconi attempted to send the first radio signals across the Atlantic Ocean, in spite of predictions that the radio waves would be lost as the earth curved over that long distance.

Detailed explanation-3: -His assistant, George Kemp, was from Cardiff, and suggested the Bristol Channel would be the perfect place to test it out. On 11 and 12 May Marconi’s team placed a transmitter on Flat Holm, an island halfway across the Channel, and began sending messages out into the airwaves.

Detailed explanation-4: -Fessenden, experimenting with a high-frequency spark transmitter, successfully transmitted speech on December 23, 1900, over a distance of about 1.6 kilometres (0.99 mi), the first audio radio transmission.