1. The problem statement, all variables and given/known data This is Purcell 7.12. Seawater moves at 1 meter/second, there is a vertical B-field of .35 gauss, and the conductivity of water is .04 (1/ohm*cm). What is the current in Amps/meter/meter? If you moved water in a bottle at this speed, would there be a current induced? 2. Relevant equations 3. The attempt at a solution I used E=(v/c)B since I know that the induced electric field comes from velocity and B-field which are perpendicular to one another... can you talk of induced electric fields like this? Then I get E=(35/c) esu/cm^2. J=σE, so J=42.4 esu/sec/cm^2. This converts to 1.4e-4 Amps/m^2. Is that the right number? I'm not sure how to answer the second part... why would it matter is the water is in a bottle or in a large body of water? All that matters it the conductivity and relative motion, so the current would flow, yes?