An infinitelly long straight wire with current I flowing along the positive z – axis is located at coordinates P ( -12 m , 5 m ) . Determine the unit vector showing the direction of magnetic field at the origin. 5 m ) . Determine the unit vector showing the direction of magnetic field at the origin. An infinitelly long straight wire with current I flowing along the positive z - axis is located at coordinates P ( -12 m October 16, 2020 Category: Uncategorised (JEE Advanced Physics by BM Sharma + GMP Solutions) , Facebook Messenger WhatsApp Share this:TwitterFacebook Related