# Signs of electromotive forces

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1. Jan 2, 2017

### Tiziano

Given this circuit, my textbook states that ℰ3 - ℰ1 = (R1+R2+R3+R4+2r) i.
Should not it be ℰ1-ℰ3 on the left-hand side, since the current enters the negative and leaves the positive terminal of ℰ1 and does the opposite with ℰ3?