CBSE Class 10 Answered
In the above experiment the wires always contain as many protons as electrons and do notaccumulate any net charge. The forces between the wires are not the electrostatic forces (Coulomb's Law), they are a consequence of the fact that electrons are moving inside the wires.Hence the field cannot be electrostatic. Moreover if we remove W2 and place a chargedconductor there, it experiences no force'. This field therefore, does not interact with stationary charges.
Further, if there is no current in the wire W2, the mutual force of attraction or repulsion also vanishes, although current in the wire W, and its field are still there. It follows,.therefore, that the field due to the current in the wire Wt acts on the wire W3 only when there is a current through it i.e., when there is a flow of charge through the wire W2.