What is helmholtz coils: Definition and 15 Discussions

A Helmholtz coil is a device for producing a region of nearly uniform magnetic field, named after the German physicist Hermann von Helmholtz. It consists of two electromagnets on the same axis, carrying an equal electric current in the same direction. Besides creating magnetic fields, Helmholtz coils are also used in scientific apparatus to cancel external magnetic fields, such as the Earth's magnetic field.
When the pair of two electromagnetics of a Helmholtz coil carry an equal electric current in the opposite direction, it is known as anti-Helmholtz coil, which creates a region of nearly uniform magnetic field gradient, and is used for creating magnetic traps for atomic physics experiments.

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  1. A

    I How Do Helmholtz Coils Affect Electromagnetic Beam Transmission?

    What would the behavior of an electromagnetic beam (transmission) be if directed through a Helmhotz coil? Is there a different result with a 4 or 6 coil configuration (all orthogonal)? Is there a direct response depending of frequency of the EM transmission (10kHz - 10 GHz) and current being...
  2. Ryaners

    Calculating B:I for Helmholtz coils

    Homework Statement I've completed an experiment where the dependence of magnetic field strength ##B## on current ##I## is measured at the midpoint along the axis between two Helmholtz coils (separation distance = coil radius ##r##). I got the expected linear relationship from the data but am...
  3. grandpa2390

    Calculating E/M for Helmholtz Coils -- help please

    edit: wait... I think the discrepancy is that I calculated Coulombs per kg? and the accepted value I was looking at was in abcoulombs per kg. If that is indeed the case, then my answer is indeed close to the accepted value of 1.76 * 10^11 Coulomb/kg. 1. Homework Statement I am trying to...
  4. S

    Comparing Series & Parallel Connections of Helmholtz Coils

    Hi, With the condition that 2 helmholtz coils are parallel with each other sharing the same axis in space . . . What are the differences between electrically connecting up the coils in series and in parallel? cheers
  5. H

    Earth's Magnetic Field Experiment / Helmholtz Coils?

    Homework Statement In my ab, we were supposed to obtain the horizontal component of the Earth's magnetic field by measuring the period of oscillation of a bar magnet in a known field using the Helmholtz coils, a resistor, and an AC power amplifier. Now during this experiment I had issues with...
  6. M

    Motion of wire in B field -vs- motion of electrons in helmholtz coils

    Hi guys, This may be a daft question (or set of questions), but I just want to bounce a few ideas off the wall once I understand some simple issues. Can anyone tell me why if you pass a current through a wire in a magnetic field, the wire will move perpendicular to the both the current...
  7. M

    Solving Helmholtz Coils: Diagram, Magnetic Field & Current

    Hi I'm suppose to find the direction of the magnetic field and the current in the diagram below and I was just wondering if I did this correctly. (red is magnetic field and blue is the current) Diagram: http://i324.photobucket.com/albums/k327/ProtoGirlEXE/100_0702.jpg And I have a few...
  8. F

    Building a Pair of Helmholtz Coils - Questions & Tips

    Hi, I'm building a pair of helmholtz coils to do a variety of magnetism-related experiments. I've borrowed an old Avo Douglas coil winder and plan to do a couple of thousand turns on two sections of 50mm or 60mm diameter pipe. Some nylon threaded rod will pass through the middle of each coil...
  9. X

    Find B Field of Helmholtz Coils

    Homework Statement We have 2 circular loops, each of radius R with current I in same direction. This is called a Helmholtz coil. The loop axes are along the z axis and the centers are at z=+/-s/2. Find the magnetic field along the z axis between the 2 loops. Homework Equations...
  10. G

    Helmholtz Coils and Iron Cores

    Hi, I'm doing a project that involves the use of Helmholtz coils. We have coils and can calculate the magnetic field produced using the standard equation and taking everything into consideration. I know we can boost the magnetic field strength of the coils by introducing and iron...
  11. S

    Calculating Magnetic Field with Helmholtz Coils

    Homework Statement The coils in a set of Helmholtz coils have 186 turns and a radius of 15.9 cm. The current is set at 2.2 A. Express your answers in units of "T" for Tesla. a) Calculate the magnetic field along the axis at the center of the two coils (x = 0). b) What is the magnetic...
  12. S

    Understanding Helmholtz Coils in CGS Units

    Working in CGS units... hence i don't know if my answer is right or wrong anymore... It doesn't 'look' right Homework Statement Two coils are placed at l and -l on the Z axis as in the figure. They both carry a current I in the same direction (anticlockwise). Both have a radius of a. (Setup...
  13. J

    How to Calculate Magnetic Field Strength of Helmholtz Coils?

    I am currently working on a research project, and need an equation or method to find the magnetic field strength produced by any number of helmholtz coils, and not just on the central axis, but at any position in the space around them. Can anyone help me out? Thanks
  14. S

    How do I take the first and second derivatives of the Helmholtz Coils equation?

    Homework Statement How do I take the first and second derivatives of the helmholtz equation? The equation is as follows: Bx= ((uR^2NI)/2) * ( [1/((x+a)^2+R^2)^(3/2) ] + [1/((x+a)^2+R^2)^(3/2) ] ) heres what I have to prove First Derivative...
  15. A

    Helmholtz coils and a Hall Effect probe

    hello, here is my second message.(and my English is still very bad) I don't understand these 3 little experiments(we need Helmholtz coils and a Hall Effect probe) I know I have to draw a graph for each situation but I can't interpret the difference between the theory and the experiment...