Cathode Ray Tube Experiments

Maltese Cross

  • A metal plate, shaped like a Maltese cross, was placed near the anode before the fluorescent screen.
  • When turned on, it was found that, the cross had blocked the Cathode Rays, and formed a shadow on the fluorescent screen..
    • This meant the Cathode Rays had relatively low penetrating power.
  • The shadow formed was a cross with very clear edges.
    • This meant that the Cathode Rays traveled in straight lines
    • This also meant that no diffraction was occuring, and thus the Cathode Ray was likely to be a particle.

Paddle Wheel

  • An extremely light, glass paddlewheel was placed within the tube along a set of runners.
  • When the tube was turned on, it was found that the paddlewheel spun, and moved towards the anode.
    • This strongly suggests that the cathode rays had momentum, and thus mass, another property of a particle.
    • It moving towards the anode also suggested the the ray came from the Cathode.

Fluorescent Screen

  • This is just a standard cathode ray tube shown here.
  • When the beam was turned on, it caused the fluorescent screen to light up as a result.
  • This meant the Cathode Rays had enough energy to produce the luminescent reaction.

Magnetic Field

  • A magnetic field was passed through a Cathode Ray Tube through the use of a magnet.
  • When turned on, the Cathode ray deflected