Practical demonstration of radiation

[colliculus]

Hi,

I'm going into a school for a day to help out with a science week and I've been asked to talk about mobile phones and electromagnetic radiation.

The age range is 14-16 and its UK GCSE level.

I'm trying to get ideas for practicals or interesting demonstrations to give, so far I've got these ideas:

i) Resonance demonstration using two tuning forks and a tray of water as the conductor. (explain that this is kind of how EMR is used to communicate with radio)

ii) Demonstration of how CDMA works by getting everyone to talk in pairs and show what happens when one person starts talking louder.

Any ideas?

I want something interesting for this age group that they can either engage in or watch me do.

colliculus

[ks_physicist]

A colleague of mine had students in the upper end of that age range bring in cell phones and, among other things, test different kinds of "enclosures" to see the effect on signal strength.

They used aluminum foil (and other things) to surround the phone, and peeked through a hole in the pouch to see what the signal strength was.

[colliculus]

good idea

then i could explain also how the signal strength can vary from place to place irrespective of enclosure just due to multipath fading effects