Question

In what respect does a wire carrying a current different from a wire, which carries no current?

Answer 1

Hint:First we have to know what is current, what it defines to use then only we can easily differentiate this above problem. Current is a flow of electric charge or in simple words we can write the flow of electrons between two points forced by voltage.

Complete answer:
We know that when electrons start flowing from one point to another with the help of a force then that elements produce an electric current. Let us first take the case of wire carrying a current, in this case the wire produces a magnetic field around it because when current flows through a wire, the electrons move inside it along a definite direction. This magnetic field can be an imaginary pattern of circular field lines surrounding a wire and the direction of this magnetic field can be determined with the help of a compass.

Now take the case where a wire does not carry any current in it, if no current is flowing through a wire, the electrons inside this wire are in random motion due to which their average thermal velocity is zero. Due to which this wire does not produce any kind of magnetic field.

Note:Never think that if a wire does not carry current, it means it does not contain any electron within it. Every element has electrons but the current will start flowing through the wire only when the electrons present in it moves along a definite direction or else their thermal velocity will be zero due to random motion of electrons.