Verifying the Radiating Long Solenoid with AC Current

  • Thread starter Thread starter sanjibghosh
  • Start date Start date
  • Tags Tags
    Ac Solenoid
AI Thread Summary
Applying a sinusoidal current to a long solenoid can produce radiation, which is a theoretical result that requires verification through experimental or theoretical analysis. A referenced paper discusses loop antennas and radiation resistance, suggesting that incorporating a ferrite rod enhances performance for AM radio frequencies. The discussion highlights the difference between radiating and non-radiating fields, emphasizing the use of various materials and configurations, such as fiberglass fishing poles, to create antennas that resonate at lower frequencies. While these antennas may not be highly efficient at low frequencies, they can still function effectively. Experimentation is often necessary to determine the resonant frequency and optimize radiation performance.
sanjibghosh
Messages
49
Reaction score
0
Recently I found that, if I apply a sinusoidal current to a long solenoid I get a radiation from it. It is completely theoretical result. I want to verify whether my result is correct or not. For this verification I need either some experimental result or some theoretical explanation whether it is wrong or correct,if correct then why this is happening?
please ,please help.
please.
 
Physics news on Phys.org
Here is a paper on loop (solenoid) antennas, including estimate of radiation resistance..
http://sidstation.lionelloudet.homedns.org/antenna-theory-en.xhtml .
Put a ferrite rod in it and it works better for AM radio (~1 MHz).
 
Last edited by a moderator:
I got the point and also I found a paper on this topic in American Journal of Physics-1995. One thing I want to know, What the basic difference between the field with radiation and without radiation is.
 
It is also fairly common to use a long piece of tubing and wind a spiral of wire onto it to act as an antenna for vehicle use.
Such antennas resonate at much lower frequencies than the length of the antenna would otherwise allow.

Blank fishing poles made of fibreglass are commonly used and the wire is wound onto the fishing pole with some spacing between turns of wire. It is usually fed from a transmitter via a coaxial cable at the bottom.

These antennas are not very efficient at low frequencies but they do work.

Usually, the resonant frequency has to be found by experimentation but a good start is to wind on about one quarter wave length of wire onto the rod and then mount the rod over a flat metal surface (a ground plane) and test it for resonance and maximum radiation.
 
Thread 'Gauss' law seems to imply instantaneous electric field propagation'
Imagine a charged sphere at the origin connected through an open switch to a vertical grounded wire. We wish to find an expression for the horizontal component of the electric field at a distance ##\mathbf{r}## from the sphere as it discharges. By using the Lorenz gauge condition: $$\nabla \cdot \mathbf{A} + \frac{1}{c^2}\frac{\partial \phi}{\partial t}=0\tag{1}$$ we find the following retarded solutions to the Maxwell equations If we assume that...
Thread 'Griffith, Electrodynamics, 4th Edition, Example 4.8. (First part)'
I am reading the Griffith, Electrodynamics book, 4th edition, Example 4.8 and stuck at some statements. It's little bit confused. > Example 4.8. Suppose the entire region below the plane ##z=0## in Fig. 4.28 is filled with uniform linear dielectric material of susceptibility ##\chi_e##. Calculate the force on a point charge ##q## situated a distance ##d## above the origin. Solution : The surface bound charge on the ##xy## plane is of opposite sign to ##q##, so the force will be...
Dear all, in an encounter of an infamous claim by Gerlich and Tscheuschner that the Greenhouse effect is inconsistent with the 2nd law of thermodynamics I came to a simple thought experiment which I wanted to share with you to check my understanding and brush up my knowledge. The thought experiment I tried to calculate through is as follows. I have a sphere (1) with radius ##r##, acting like a black body at a temperature of exactly ##T_1 = 500 K##. With Stefan-Boltzmann you can calculate...
Back
Top