Trying to clear concepts of electromagnetic waves
I have a few queries regarding electric field magnetic field and propagation of electromagnetic wave.
1.Constant Electric field is defined as voltage per unit length. If i have a DC battery connected as follows:
2. In the above configuration if the two ends of wires were shorted to each other then will there be an electric field?
3. Is voltage also a form of electric field? Am I right when i say the following statement: Voltage is required to move a charge through a conductor against the resultant electric field due to other charged particles through a conductor?
4. If instead of a battery I use an AC source in the above configuration. Then the red and black wire should act like a dipole antenna. But since the red and black wires are still open circuited, there will be no current flowing. If there is no current flowing through the conductor then there will not be any magnetic field created and the conductor should not act like an antenna at all. Kindly help me answer this question.
5. The most important question. Due to varying voltage applied on a conductor completing a circuit, varying electric filed is produced around the conductor, or is it inside the conductor? Also due to this varying voltage there will be varying current setup in the conductor which will create a magnetic field around the conductor. Now even if i do believe that an electromagnetic wave has been setup, how will it ever leave the conductor to get radiated away from a conductor? I mean what makes it leave the conductor at all?
I know these are very simple questions. I hope i have put them across properly. I am an amateur at this and i am dying for answers, I would be really grateful if someone helped me out.
Regards
Take a “visual tour” of electromagnetism here:
http://web.mit.edu/8.02t/www/802TEAL...dtour/Tour.htm
Hi,
Thanks for the link. It was very useful. I still have a few queries
1. For the diagram that i posted in the previous post, there exist an electric field between the two ends of the conductor, but no magnetic field because there is no current flowing. But after reading the material in the link, they have stated that whenever and electric field exist there has to be a magnetic field perpendicular to it. How do you explain that in the diagram from previous post?
No, read more carefull, the basic law is the Biot-Savart Law for the magnetic field of a point electric charge moving at a velocity v.
If you have an electrostatic field, your case with battery connected, than no magnetic field exists. If the value of electric field changes with time, the magnetic field perpendicular to the electric field is produced, or if you short circuit your batery the same happens.
In your case it produces a static electric field with no magnetic filed.to produce a magnetic field the electric field should vary with time.