How is the electric field near a solenoid?

Question

I know that moving charges produce both magnetic and electric fields. The image given below is of electromagnetic field. I was able to identify the magnetic field. But,I do not know where the electric field is?

Answer 1

This lecture gives a good overview of this. http://faculty.uml.edu/Andriy_Danylov/Teaching/documents/L18Ch33InducedEcovered.pdf (Pg: 11-12)

Lenz's law provides a lot of insight into this question. An AC solenoid will induce a changing magnetic field. This changing magnetic field acts to impede the current direction in the solenoid, so from here, you can likely already see that the electric field is made in the direction that opposes the electric field in the wire driving the current.

Answer 2

First let's assume DC. The electrical wire is neutral: as many negative electrons as positive atomic nuclei in any part of the wire. Thus there is no electrostatic field outside of the wire and the lines represent the magnetic field lines. However for the electrons to move through the wire, there needs to be an electric field. This field is localised inside the wire, and it is on average always along the direction of the wire, thus winding up as the solenoid winds up. This field strength is also constant, and with a good approximation, uniform along the wire.

Now if the current was AC, the magnetic field would vary with time, its strength at any point passing through a maximum, then declining to zero, changing direction and reaching a maximum in the other direction, to then decline again, etc. A changing magnetic field creates a changing electric field according the Maxwell equations which rules electromagnetic phenomena (i.e. electric + magnetic + their interplay). So in this case, there would be an electric field outside the wires. I don't know what it would look like for the exact situation of your diagram, except in the central zone of the solenoid where the magnetic field is nearly uniform, and its direction along the axis of the solenoid: in that zone, the electrical field induced by the varying magnetic field would be radial. I am sure you can draw a diagram yourself!