Electromagnetism & Motors

e/m Apparatus with tube EM-4N


[Product Description]

E/M apparatus with tube (without power supply)

[Overall Advantages to Users]

  • The ratio of charge over mass for an electron can be calculated using the diameter of the circular path, the current applied to the Helmholtz coils, and the voltage used to accelerate the electrons.
  • Permits students to clearly observe the effects of electric and magnetic fields on an electron stream.
  • Compact and affordable all-in-one unit that provides students a dramatic and visually pleasing experience.


  • Specific charge of electron
  • Electric charge of electron



Related Products


[To all users]

  • Glass-vacuum tube has a built-in phosphor coated engraved glass rod with a scale along the central axis, which eliminates parallax when making diameter readings of the electron orbit.
  • Easy to observe the entire experiment through the front view hole or rear sliding panel.

[To teachers]

  • Helium gas sealed within the tube facilitates the production of a bright, clear view of the electron beam.

[To students]

  • Built-in electrode in the tube absorbs electrons after being emitted from the electron gun and traced their circular path, which prevents the circular tracing of the electron path from being disturbed by previously emitted electrons and/or becoming in spirals, contributing to more accurate measurement and extended operating life of the discharge tube.
  • Material of housing: Plastic (Acrylate resin)
  • Vacuum Tube: – 130mm diameter – Helium gas – Integrated phosphor scale
  • Helmholtz Coil: 300mm diameter, 1mm wire 130 turns, Two parallel mounted coils with variable resistors to adjust current
  • Anode: 200-500V
  • Heater: 6.3V/1A
  • Helmholtz coil: 12V DC/2A
  • Dimensions: 37cm x 25.5cm x 39cm (L x W x H)
  • Net Weight: ca. 7 kg

Teacher's Resources

  • [MANUAL] in English for this product.


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