1. The problem statement, all variables and given/known data A conducting rectangular solid of dimensions dx=5m dy=3m dz=2m moves at a constant velocity through a uniform magnetic field B=(30mT)j. What are the resulting a)electric field within the solid,in unit vector notation? b)potential difference across the solid? 2. Relevant equations ●Electric Force=qE ●Magnetic Force=Bqv ●E=V/d ●Basic theory of Hall effect:On applying a magnetic field perpendicular to the block,some electrons get accumulated at one side of the block due to the magnetic force acting on them,which after a while causes an electric field to be produced inside the block across it's width ,which opposes and finally cancels the effect of the magnetic field. 3. The attempt at a solution I think the velocity ought to be mentioned in the question. It just says constant velocity.That could mean the block is moving either across the x axis or along z axis. (Only then will Hall effect be observed and an electric field and hence potential difference will be observed) Then,we can just equate electric and magnetic force (equations meantioned above) And first find out E,then through the 3rd formula V. However,I find out both E and V in terms of v, to see if both the answers correspond to the same v as they should,and the answers matching(for a velocity of -200i,but we are not supposed to do that :p) So,in a nutshell:Can I do this question without knowing the velocity before-hand??