mrmackenzie
solutions to unit 2 practice NAB
Here are the solutions to the North Berwick practice NAB for unit 2.
Higher unit 2 – practice NAB
Your unit 2 NAB is on Friday. Here is a practice NAB from North Berwick High School. I’ll post the answers separately.
electrical wiring at home – the ring circuit
Wikipedia has a good description of how a ring circuit is used in home wiring. The diagram below is neater than the one I drew on my board in class. You can click on it to view a larger version of the drawing.
drawing by Andrew C.
- The ring circuit for power sockets is rated at 30A.
- The ring design allows electricity to reach the socket from two different directions, so the current flowing in any one wire is lower.
- Since the current is lower, a thinner cable can be used. This saves money as copper is expensive.
Click below to download the Scout guide to home wiring.
Using excel for AH Physics investigation graphs
We spent some time today looking at ways of analysing data obtained from your investigation experiments. It is often a good idea to generate a graph of your results. Your graph does not have to be drawn by hand, it can be produced on a spreadsheet. If you do decide to use a spreadsheet, remember to print the gridlines on your final version of the graph.
If you use Excel, there is a function called linest that can be used to determine the gradient of the best-fit line and the intercept with the y-axis. If you follow the instructions below, the linest function will also calculate the uncertainty in the gradient and intercept point for you.
Here is a linest tutorial to get you started. It also includes instructions on how to add custom error bars to your graph.
Excel Tutorial: Using LINEST function, Plotting a graph, Adding Error Bars
I have included a pdf of a different help sheet – download it using the link at the end of this post.