# Positive emf? What does positive emf mean?

Could someone please explain to me why we want to take the "magnitude" of the emf?

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Just reinforcing @jak and adding my own two pence here really.

I think it is because you are not trying to determine the motion of the current, therefore you don't need it. I also think you don't have enough information to determine the sign.

There is no N number of coils in this, but I think the texas note has a nice example of an induced emf problem, which may help you visualize what is going on. Though is is a bit different to your question. Essentially the direction of the emf tells you whether the current is clockwise or anti-clockwise round a coil.

The texas notes have helped me with a few emag problems so it's worth having a look at them generally, in my view.

Also, although it is not explicitly asking for magnitude in the text. It does seem to be using the magnitude symbol in the mathematical notation, so that would be them asking for the magnitude of induced emf, right there.

Hope that helps.

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Is it wrong to add a minus sign? –  sidht Aug 16 '12 at 0:47
Generally or for your question? Your answer should be in the form $|\varepsilon|=6.28mV$. –  Magpie Aug 16 '12 at 13:06
For my question. –  sidht Aug 17 '12 at 20:54
yes @jak see post above. A modulus sign means it is a magnitude. You cannot have negative magnitude. –  Magpie Aug 18 '12 at 1:07
No I meant not giving the answer as the magnitude –  sidht Aug 26 '12 at 23:25