Topic: Ampere's law: straight wire and solenoid· Magnetic Effects of Current and Magnetism
From Ampere's circuital law for a long straight wire of circular cross-section carrying a steady current, the variation of magnetic field in the inside and outside region of the wire is :
1. a linearly decreasing function of distance upto the boundary of the wire and then a linearly increasing one for the outside region.
2. uniform and remains constant for both the regions.
3. a linearly increasing function of distance upto the boundary of the wire and then linearly decreasing for the outside region.
4. a linearly increasing function of distance r upto the boundary of the wire and then decreasing one with \(1/r\) dependence for the outside region.