Fields of Moving Charges

Maltese Cross CRT

[M | t | ★★★]
Maltese cross obstacle and fluorescing glass show that electrons in a Crookes tube travel in straight lines and are affected by magnetic fields.
[In-Depth Description]

Cathode Ray Deflection

[M | t | ★★★★]
Small Crookes tube with built-in fluorescent screen shows electron beam deflection by magnetic field.
[In-Depth Description]

TV Image Deflection

[L | t+ | ★★]
Image on black and white television is deflected by a magnet, not unlike the Maltese Cross.
[In-Depth Description]

Flicker Bulb

[M | t | —]
A magnet placed near this commercially available light bulb causes the filament to vibrate at 60 Hz, producing a "flickering" effect.

e/m Apparatus

[L | t+ | —]
An electron beam is deflected into circular or spiral paths by a magnetic field.

Force Between Parallel Conductors

[L | t | ★★★★]
A strong surge of current from a 12V truck battery causes parallel wires to exert a force on each other.

Jumping Wire

[L | t+ | ★★★]
Motor effect on conductor between poles of horseshoe magnet.
[In-Depth Description]

Boxtop Loudspeaker

[M | t+ | ★★★★]
Make a crude but effective loudspeaker from a cardboard box, coil of wire, and a magnet

Magnetically Accelerated Axle

[L | t+ | —]
Current carrying axle on rails experiences force from electromagnet.

Current Carrying Electrolyte

[S | t+ | —]
Electrolyte circulates in magnetic field.

Magnetohydrodynamic Propulsion

[M | t+ | ★★★]
Demonstrate how to propel a boat or submarine without moving parts.

Contact Us

Mailing Address: Lecture Demonstration Services, Science Center, Rm B-08A, 1 Oxford Street, Cambridge, MA 02138
Campus Location: Science Center B-08A | Tel: (617) 495-5824 | Email: scidemos-at-fas.harvard.edu