How to remember + or - (version 1)
On a battery or diagram, which is the +ve and which is the -ve end?
To remember the +ve end, first decide whether a +ve symbol ( + ) or -ve symbol ( – ) has a longer line in total:
As you can see the +ve needs a longer line in total, i.e. `a+b\ \mm`.
So, in the diagram below, which is the longer line: `x\ \mm` or `y\ \mm`?
Again, it's easy to see that `x\ \mm` is the longer line.
We match the two longer lines together, i.e. the +ve with the longer line. Hence the electrical diagram is marked:
Now, on a real battery, we can use the same idea.
So which is the longer line: `a+b+c+d+e\ \mm` or `f\ \mm`?
Again, it's easy to see that `a+b+c+d+e\ \mm` is the longer.
So we match the two longer lines together, i.e. the +ve with the longer line. Hence the battery is marked:
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![](/images/user/base/Maths/Logarithms/Reference%20Tables/reference-anti-log-table-1.b0b0513.jpg)
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