Does a moving charge create a magnetic field or does a changing electric field create magnetic field or are they same? and a moving charge always creates a changing electric field?
Here is a thought experiment to show what I mean :
Imagine a conductor thats an infinite line of charge on a Z-axis in some imaginary space . and the current is always flowing ( constant current , $dI=0$ )
We place two device ( lets name it $A$ and $B$ ) at the same point in space ( its not possible , but imagine it is ) , These two devices can independently measure the electric field and magnetic field respectively .
Okay , lets go to $t=0$ ( we are not stopping anything , the electrons were still flowing at $t=-0.00001$ , you can say we are taking the readings at that time , not stopping anything ) , we take the values of the readings of the two devices
Lets suppose the values are
Now we take the readings at some other time $t$
Lets suppose those values are
Heres the problem now : Due to constant inflow and outflow , we can say that at any point in time , there is always a set amount of electrons in every point ( eg (0,0,5) ) , hence the electric field remains same always
Now since electric field always remains the same ( $E_1=E_2$ ) , but there being movement of electrons , will there be Magnetic field ( will $B_1 >0$ or $B_2>0$ )? and the answer to that is YES ! Because our book tells us that a current carrying conductor has some magnetic field . So the question is : Why ? Even when Electric Field is not changing? Does magnetic field only depend on movement of electrons and not change of electric field at a certain point ?
Now obviously there are many shortcomings in this question and it will probably be very wrong in the concept somewhere.
As one of my friends pointed out , that electrons dont just teleport , they need time to move ( albeit very short time ) , his theory is that , in the time that the electrons move , electric field changes but then again comes back to the same value . Hence he says that electric field is changing , therefore there is a magnetic field .
Also , I assumed that electrons move in a straight line , which may or maynot be true ?