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Need help with Eduqas A Level physics resistivity question

So I'm doing this past question from the "resistance" topic, and I am stuck on part b). I was able to get 3/4 of the marks by working out that the cross-sectional area is 8.55x10^-8 m^2. However, the mark scheme then says tresistance.png
hat the thickness would be 7.1x10^-5 m and I have no idea how to get to that answer. Could anyone please help?
(edited 1 month ago)
Original post by College student2
So I'm doing this past question from the "resistance" topic, and I am stuck on part b). I was able to get 3/4 of the marks by working out that the cross-sectional area is 8.55x10^-8 m^2. However, the mark scheme then says tresistance.pnghat the thickness would be 7.1x10^-5 m and I have no idea how to get to that answer. Could anyone please help?
You’ve got to think about what specifically they’re asking in the question. They’re asking for the thickness of the wire. The cross sectional area we have calculated is equal to the width of the wire multiplied by the thickness of the wire.

I’ve put my workings below, try doing it without my workings and see what you get.
Just remember that it’s a rectangular wire, and the cross sectional area of a rectangle is the width x thickness (height).

1246EFB7-C931-4DC9-910F-896A09D796E6.jpeg

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