Australia's Science Forum

Hi,
There is a prac in the new Pearson Physics text for year 12 (prac 6.2) that does not specify what type of power supply is needed for the bundled cable. Is it a power pack or a battery pack? Any feedback for this prac would be appreciated.
Thanks.
Annette.

Hi Annette
LOL I've just been asked to sort this one too .( not Pearsons but the same thing)
After a bit of mucking about yesterday I found that if you use wire , it requires a lot of current , in excess of what our typical power supplies can supply before tripping out to get a visible deflection .....barely 0.5mm

I substituted the wire for two strips of alfoil about 500mm long and about 12mm wide spaced about 10mm apart , I could get attraction and deflection of around +/- 5mm on each foil strip using a power supply but it still tripped after a few seconds if left connected but long enough to clearly observe the effect .

Google shows folk using wires needing a Battery( small car or motorbike ) but be careful .....such high currents can quickly cause thinner wire to glow red hot and melt . Watch for burnt hands and benches .

Thank you!!

We use alfoil 250mm long, 12mm wide and 20mm apart attached to firm pieces of cardboard either end. Works well