## Nali Group Title When is Emf= vBl negative like (Emf=- vBl ) and when is it positive? 7 months ago 7 months ago

1. theEric

http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html The emf would be negative if the vector $$\vec v\times\vec B$$ is negative. It depends on your coordinate system, how you allocate the signs. But you can always look at the velocity and magnetic field vectors. In this drawing, the current will be out of the screen.|dw:1397363101158:dw| Swap the vectors, and it will be into the screen. Check out the right hand rule! :)

2. Nali

thanks!

3. theEric

You're welcome! When I answered this, I was in a rush. Let me know if you have any questions!