Consider a long straight wire of cross sectional area A carrying a current I.let there be n free electrons per unit volume.An observer place himself on a trolley moving in the direction opposite to I with a speed I/neA and separated from wire by distance r.The magnetic fields observed by person equal.
Consider a long straight wire of cross sectional area A carrying a current I.let there be n free electrons per unit volume.An observer place himself on a trolley moving in the direction opposite to I with a speed I/neA and separated from wire by distance r.The magnetic fields observed by person equal.