Here are some useful sites to supplement the work we did on Electricity yesterday.
Firstly – the Flash file with questions about circuits came from the Essex e-gfl site. You can see it here.
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 pathway 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)
Here are some more links that hopefully will help with teaching circuits
The free circuit builder Crocodile Elementary is now called Yenka Basic Circuits, and you can get it here. This will let you build circuits to your heart’s content!
For a quick 10 minute preview, that explains some aspects of circuits. Go to Furry Elephant, and choose series or parallel circuits. It literally only allows you 10 minutes though.
Here’s a new site that may be useful, What Works Well. I saw this at Teachmeet and it looked like it’s something to bookmark and keep an eye on.
WhatWorksWell is a growing database of case-led studies which describe learning improvement. It’s the place where teaching practitioners can share real studies which have improved learning and teaching. They are ‘case-led’ studies because they start and end with the learning needs of the pupils and the difference made to their progress. You can browse or search for case studies relevant to you. If you register, you can add your own case-led study to describe the impact of your own work on pupils’ learning.