1. The problem statement, all variables and given/known data An infinitely long straight wire of radius a = 0.01m carries a total current I = 1A uniformly distributed over the area of the wire. An electron with instantaneous velocity (at time t ) v = 1000ms directed parallel to the wire (in the same direction as I ) is r = 0.1m away from the wire centre. What are the magnitude and direction of the force acting on the electron at time t due to the magnetic field B produced by the current? 2. Relevant equations F=qV x B 3. The attempt at a solution F=qV x B =qvBsinθ =qvB B=μ0I/2∏r My question is how to handle the radii? Would you calculate from the centre of the wire or the surface of the wire? And in regards to the direction of the force if v is along the paper B would be into it and F would be down it. Does this all seem correct?