When referring to electroMagneticwaves is the electric field mono or bi polar?Smugkl85 - 6 Answers
Basically an electro-magnetic wave is a radio signal that has a positive and negative peak and so the voltage swings around a mean on a radio frequency. So while you could say it is "bi-polar" not mono-polar they are not terms normally used in radio or electronic theory.
Radio transmitters generate the radio frequency waves which is known as the radio frequency Carrier Wave. That could be continuous wave such as in transmitting morse code, but normally today the carrier waveform is MODULATED by an audio waveform. That may be speech, music or other audio sounds.That information is therefore the modulating signal which gets converted into an electrical signal and then injected in some way into the radio frequency power amplifier stage of the transmitter.
The modulation may be amplitude modulation (AM) transmitted on low, medium or high frequencies (i.e. between about 100 kilohertz and 30 Megahertz) or Frequency Modulation (FM) transmitted on Very High Frequencies (i.e. between about 87 megahertz and 160 megahertz). So at the transmitter a transducer, such as a microphone, is used to change the sound into an Audio Frequency (i.e. between 20 hertz and 20 kilohertz) that becoming the audio component in the electrical signal prior to the modulation of the electromagnetic carrier wave, then both get radiated together from the transmitter aerial or antenna into free space.
The positive peak and negative peak voltage of the radio frequency carrier wave and the audio frequency modulated component alternate around a mean which is known as earth or ground potential in the transmitter and receiver. So the audio information is in the SIDEBANDS of the radio frequency carrier wave, although radio telephony transmissions may be upper or lower sideband or double sideband. Lower Sideband means the audio information is only contained in the negative peak of the radio frequency carrier wave signal as it is radiated through free space, double sideband means the audio information is contained in both the upper and lower sidebands.
The term dielectric in electronic terminology means the insulation between the plates in a capacitor. Dielectric is not a term used in describing an electro magnetic waveform in radio theory terminology and there is no insulation of any kind contained in the waveform. The duration of the mean as well as the positive and negative peak voltage swings is continuous so long as the electro magnetic radiation continues to be emitted by the radio transmitter.
The radio frequency carrier signal can be picked up by an AM or FM radio receiver by tuning to the frequency of the transmission. The receiver circuit will then extract the audio information contained in it and then the audio amplifier and another transducer such as a loud speaker or headphones will amplify it, so a person listening can hear a faithful reproduction of the voice speech or music that was originally injected into carrier wave at the transmitter.
EMWs are postulated to be iterative electric and magnetic fields. The electric and magnetic fields belong to the same plane; but are perpendicular to each other. If they did interact, it would be a cross-product of the vectors that represent the fields: The resultant is a single vector. For propagation to happen then the plane describedby thefields has to be projected along a path collinear with the resultant vector.
As forthe box: the box: it encloses a 120VAC/12VAC tranformer sonnectected to a full-wave bridge. The output of the b ridge is connected to a 60,00uf electrolytic capacitor. The capacitor has a resistor across it as a load so the capacitorwill charge and discharge in synch with th fukll-wave signal. The positive terminal of the capacitor id connected to a feed-thru terminal (thru side of box) thru a resistor to limit the secondary coill (of the transformer) current if the feed-thru terminals are shorted. A conductor, terminated with a sphere is connected to the feed-thru terminal (outside of box). One as[ect of the experiment is shorting the feed-thru terminals causing a varying current in the connecting conductor (wire). A compass is placed int the proximity of the flowing current rhje variation of magnetic flux is indicated. When a compass is place in the proximity of the spheare, without the short, then no magnetic flux is indicated. Any magnetic flux produced by the transformer or wire connections are enclose in a steel box so the box will divert any magnetic flux thru it (like a motor stator) or a transformer core). The information logged is current, capacitor charge, capacitor voltage and instantaneously generated magnetic flux.
I'm doing an experiment that encloses all magnetic fields in a steel box, and extend the positively charged plate of a capacitor 1 m from the box. The variation of charge on the capacitor plate varies with a full-rectification signal, A compass is placed in many possible locations around the mono-pole (and logged) to check for magnetic flux. This experiment shows that an elctric field does not produce magnetic flux. A corollary from this experiment shows electromagmetic waves dont exist: because varying electric and magnetic fields do not iteratively interact. Static elexctric fields are not electeo0ns moving (current). Current going through a wire does produce mnagnetic flux. A wire moving in a magnetic field does create a current in the wire (both are predictions in motor theory and consistent wth observations)....
Electric fields are produced by electrical charges, positive and negative. Electric fields are also produced by changing magnetic fields.
Magnetic fields are produced by moving electric charges. There is no magnetic monopole in nature, so far as anyone has been able to discover.
Electricity and Magnetism are intertwined. When referring to electromagnetic waves we are talking about the propagation of electromagnetic waves through space; this could be light, radio waves, or high energy gamma rays and everything in between. The electric field goes positive and negative in direction. It is a transverse wave. Similarly the magnetic field is at right angles the the electric field and goes positive and negative. Both fields are perpendicular to the direction to propagation.
You have a positive plate of a capacitor not too near a steel box. The negative plate is where? In order to have capacitance you need both plates.
A compass placed outside the box does not deflect; therefore, there is no magnetic field except for the Earth's field. What is the monopole? Is it the electrically charged plate?
A static electric field does not produce a magnetic field. Granted. How exactly does this show that electromagnetic waves do not exist?
The negative terminal of the capacitor is also connected to a feed-thru terminal ....