Teaching Science » electricity

Squishy Circuits

Danny Nicholson — Mon, 04 Apr 2011 19:41:50 +0000

In an excellent demo at TED U, AnnMarie Thomas shows how two different flavors of homemade play dough can be used to demonstrate electrical properties — by lighting up LEDs, spinning motors, and turning little kids into circuit designers.

More info here.

Lords of Lightning

Danny Nicholson — Sun, 06 Feb 2011 14:51:03 +0000

Teaching about Electricity? This video from the New Scientist blog about the Lords of Lightning act should spark some interesting class discussions…

Read about it here.

Talk about Tesla Coils, what is causing the sparks, what kind of suit must the men be wearing to not be killed by the massive voltages involved etc.

Plus, it’s pretty spectacular.

Science Poetry Books

Danny Nicholson — Sun, 07 Nov 2010 08:13:33 +0000

Succeeding with Science has 2 very handy books for KS1 teachers who want some poems to use in lessons about Light and Dark and Electricity.

These are: “Electric Man’s Big Book of Poems About Light And Darkness” and “Electric Man’s Big Book of Poems About Using Electricity“. They were written specifically to support KS1 Science unit 1D: Light and dark, and unit 2F: Using Electricity, the ‘shared text’ have been devised to be integrated within the National Literacy Strategy.

Each book contains eight fully illustrated poems and are both available as a free download from the Succeeding with Science page here.

There are some other useful free resources on that page which are worth a look.

Also take a look at the rest of the site as there are some fun little free Online Games which you might also find a use for.

Circuits

Danny Nicholson — Thu, 19 Jun 2008 12:55:47 +0000

To answer another one of the questions you submitted. Trying to explain why the brightness of bulbs in a circuit changes can be tricky. It can be helpful to imagine different analogies/models to explain what is happening.

A very nice place to start is this presentation from Skool.co.uk

A battery with one bulb connected is your standard to compare things to. Electricity flows from one end of the battery to the other, flowing through the bulb as it goes, making the bulb light up.

Adding a second bulb in series will increase the total resistance in the circuit. The bulbs will be dimmer than the single bulb.

Adding a second bulb in parallel is a different situation. You have added a second parthway for the electricity to flow, The resistance is greater than a single bulb, but is is not as high as the two bulbs in parallel. The two bulbs will be brighter.

A “cars on the highway” analogy may help explain the distinction: think of a wide highway narrowing to a one-lane bridge to cross a river. Now imagine that in order to get rid of traffic jams, the highway department builds another one-lane bridge over the river. The “resistance” (in this case analogous to the width), of both bridges stays the same, but the amount of “current” or traffic that can cross the river has increased, so the overall “resistance” of the entire system has decreased. Taken from here.

In a series circuit, each bulb you add will make the brightness of the bulbs dimmer and dimmer

In a parallel circuit, the brightness of the bulbs does not change with the addition of more bulbs (but if you added many parallel circuits, eventually all of the bulbs would dim down as you approached the capacity of the battery)

This page from the BBC KS2 Bitesize site is pretty useful.

The GCSE Bitesize page may help explain things to you too.

Link to other Links Pages

E=TC3 6G Changing Circuits Page

E=TC3 4f Circuits and Conductors Page

TopicBox – Electricity