02 Lorentz Force (1)

Aim¶

To show that a current in a magnetic field experiences a force.

Subjects¶

• 5H40 (Force on Current Wires)

Diagram¶

Equipment¶

• Spiral filament lamp.

• Safety connector to mains ($220\mathrm{~V}/50\mathrm{~Hz}$).

• Bar magnet.

Presentation¶

The lamp is connected to the mains and the filament is glowing. The filament can be seen clearly.

The bar magnet approaches the lamp and the individual turns of the spiral filament show themselves as broadened bands (see Figure 2). The filament performs a fast reciprocating motion

Explanation¶

The reciprocating motion of the filament indicates that a force is acting and that it is acting to and fro.“To and fro” is caused by the constantly changing direction of the current ( $50 \mathrm{~Hz}$ ).

Sources¶

• Biezeveld, H. and Mathot, L., Scoop, Natuurkunde voor de bovenbouw, part 4/5 vwo, pag. 200 and 210

• Mansfield, M and O’Sullivan, C., Understanding physics, pag. 486-487