Month: March 2011
solutions to unit 2 practice NAB
Here are the solutions to the North Berwick practice NAB for unit 2.
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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.
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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.
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