Additional Info

• ID Code: K1-11
• Purpose: Demonstrate visually the force between two parallel currents.
• Description: The discharge tube produces an electron beam moving from left to right, which can be seen on the fluorescent screen inside the tube. Activating an electric current in an external wire held along the top of the discharge tube, parallel to the electron beam, deflects the electron beam a small distance up or down. If the direction of the current in this wire is reverse, the direction of the deflection will likewise reverse. This illustrates the vector nature of the force.

  The photographs above show the displacement of the beam when the positive current in the wire is running (a)left-to-right, at left above, and (b) right-to-left, at right above. This is a small effect; a picture with no current in the wire is reproduced at the bottom above for reference. Using the switch to turn the current ON and OFF while watching the beam shows the effect VERY clearly.

  If desired, a video camera may be requested to display this demonstration on the projection screen in the large lecture halls.

• Availability: Available
• References: REFERENCES: (PIRA 5H30.15) See Demonstration K1-01: FORCE BETWEEN CURRENT-CARRYING WIRES.
• Loc codes: K1, PW1