Which pioneer scientist used radio waves to transmit signals over distances of several kilometres in the 1890s? 

The correct answer is Guglielmo Marconi.

Key Points

• Guglielmo Marconi was an Italian inventor and electrical engineer.
• He conducted pioneering work in long-distance radio transmission.
• Marconi developed a practical radio wave-based wireless telegraph system in the late 19th century.
• His system was able to transmit signals over distances of several kilometers.
• Marconi's contributions helped significantly expand the field of telecommunications.
• His work was recognized internationally when he was awarded the Nobel Prize for Physics in 1909.​

Additional Information

• Michael Faraday:
  • Michael Faraday was a British scientist who contributed significantly to the field of electromagnetism and electrochemistry.
  • He discovered electromagnetic induction, diamagnetism, and the laws of electrolysis.
  • Although Faraday discovered electromagnetic fields, he did not work on radio wave transmission.
• Paul Langevin:
  • Paul Langevin was a French physicist.
  • He is known for his work in developing Langevin dynamics and the Langevin equation.
  • He developed the use of ultrasound using piezoelectricity but wasn't involved in radio wave transmission.
• Pierre Weiss:
  • Pierre Weiss was a French physicist known for his work in magnetism.
  • He introduced the concept of magnetic domains, which helps explain the magnetic behavior in ferromagnetic materials.
  • His main work was on magnetism, not on radio wave transmission.