Double Induction Coils with Cathode Ray Tube

As AC current is sent through a large inductor coil, the magnetic field produced by the coil changes in direction and magnitude. The cathode ray responds to the changes in magnetic field by moving and twisting with the current.

Setup:

Plug both the inductor coil and cathode ray tube into their respective power sources. The power source for the coil should be AC power. Make sure the power source for the coil is connected to the AC ports.

Turn on the power to the heat gun in the cathode ray tube. Let the cathode ray tube slowly warm up. A small orange glow should be seen inside the tube.

Once the glow is seen, turn on the power to the electron beam. A thin green beam should be seen in the tube.

Turn on the AC current to the big coil.

Move the cathode ray tube around the coil and watch the beam spiral and move.

Notes:

This demonstration is not currently available.

The electron beam in the cathode ray tube may not point directly straight to begin with. Take note of the original position and continue the demonstration as described above.

Equipment Needed:

  • Power source for inductor coil

    • Can be PASCO 850 or generator attached to the base of the cart

  • Power source for cathode ray tube

    • Must be capable of at least 200 volts

  • Inductor coil on rolling cart

  • Banana cables

  • Cathode ray tube