1. The problem statement, all variables and given/known data Electrical current is flowing along a long, straight wire that has a shape of a half-cylinder of radius R. Cross-section of the wire is shown, current is directed out of the plane of the picture. Current is distributed uniformly along the wire and has total magnitude I. Find magnetic field B at the point O on axis of the wire. 2. Relevant equations dB = [itex]\mu[/itex]0/4pi (IdlXr)/r^2 3. The attempt at a solution Here's what i don't get? is this saying that the wire is cut in half and is only a half cylinder and current is coming out? or is the wire bent in a half cylinder and is asking for the mag field at a distance R? btw the point O on the axis is literally the center of the circle. From O to to anywhere on the semicircle is the radius R. I'm confused as to the meaning.