GENERAL KNOWLEDGE

Detailed explanation-1: -In fields including electric power generation, mass media, sound recording, and motion pictures, he invented various devices.

Detailed explanation-2: -During the first months of 1879, Edison designed a dynamo that differed in important ways from contemporary designs. Many contemporary electrical experts thought a generator would work best when its internal electrical resistance was equal to the external resistance of the circuit.

Detailed explanation-3: -By January 1879, at his laboratory in Menlo Park, New Jersey, Edison had built his first high resistance, incandescent electric light. It worked by passing electricity through a thin platinum filament in the glass vacuum bulb, which delayed the filament from melting.