Comparing Hall Voltage of Bars 1 & 2

[bbuilder]

Homework Statement

Two metal bars, 1 and 2, are identical in all ways, except that bar 2 has twice the width of 1. The bars are parallel to each other, but far apart from each other, in a uniform magnetic field and carry the same amount of current in a direction perpendicular to the field. How does the Hall voltage of bar 2 compare to that of bar 1?

Homework Equations

The equation for Hall effect is nq=(-JB/E). I know that I can relate E to V by using E=(V/d).

The Attempt at a Solution

If the width of bar 2 is twice the with of bar 1, then (because of E=V/d) the voltage of 2 would be two times greater than bar 1. I'm confused about why I need to use the Hall effect if I can just use E=V/d.

 

[Simon Bridge]

Compare: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html#c2