this site is moving…

Many of you have encountered error messages while using this site.  It’s outgrown the current hosting service and I’m moving to a new provider.  Please bear with me while I transfer everything across to the shiny new server.

If you discover any links that have stopped working, please leave a comment in the affected post/page and I’ll fix them as they are reported.  Thanks.


Sorry if you’ve encountered a maintenance screen this week.  My site was hacked and I had to reinstall everything from scratch.  Most things should work but please leave a comment if something is broken and I’ll get it fixed as soon as I can.

ah – particle physics

So we’ve reached the end of unit 2. For those of you interested in finding out more about fundamental particles, here are some ideas to get you started.

how satellites rule our world

BBC2 showed a really good programme about satellites last night.  This screenshot showing a satellite passing over the Highlands is taken from about 17 minutes into the show.  Click on the picture to visit the BBC’s own page about the documentary.

It was quite eye-opening to see just how much modern society relies on satellite technology.

You can download the entire programme using the link below.

capacitors – charge, energy and graphs

We’ve just completed the topic on capacitors in dc circuits, finishing off with a detailed study of the graphs obtained for current & voltage against time when a capacitor is charged or discharged through a series resistor.  There are some additional notes and practice questions at the end of this post but please watch the clips first.

This introduction to capacitors from the nice people at Make Magazine is a good starting point.

The S-cool revision site has some helpful notes and illustrations on capacitor behaviour; try page 1 (how capacitors work) and page 2 (charging and discharging).

Here is a video that covers some of the areas we discussed in class. Ignore the maths at the end of each section of the film, you won’t need it.  Notice how the man in the film uses a lightbulb, rather than an ammeter, to show when the current is large or small.  Clever, eh?

One use of capacitors you should know about is the flashing lamp.  We’ll cover this application next week.

Blinking Neon Bulb (5F30.60A) from Ricardo Alarcon on Vimeo.

I compared normal electrolytic capacitors to a 10F supercapacitor, and we observed its superior performance in terms of energy storage.  This video goes one step further and shows the fun you could have with an ultracapacitor. Do not try this at home!

Of course, you can always make your own capacitor with paper and electrically conductive paint.

Now download the pdf below. It contains notes to help with your prelim revision and some extra capacitor problems.

Thanks to Fife Science for the original pdf from Martin Cunningham.

site maintenance

I am moving this site to a new hosting company during the holidays.  You might notice some broken links or missing videos.  Please let me know by leaving a comment so I can fix anything I have missed.

Past papers are currently unavailable on the AH, Higher & Int2 pages.  Some (not all) can be found by typing “pastpaper” in the search box at the top of the page.