# What is Field strength: Definition and 367 Discussions

In physics, field strength means the magnitude of a vector-valued field (e.g., in volts per meter, V/m, for an electric field E).
For example, an electromagnetic field results in both electric field strength and magnetic field strength.
As an application, in radio frequency telecommunications, the signal strength excites a receiving antenna and thereby induces a voltage at a specific frequency and polarization in order to provide an input signal to a radio receiver. Field strength meters are used for such applications as cellular, broadcasting, wi-fi and a wide variety of other radio-related applications.

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23. ### A Verifying the Relation in Yang-Mills Theory with a Scalar Field

I'm trying yo verify the relation $$[D_{\mu},D_{\nu}]\Phi=F_{\mu\nu}\Phi,$$ where the scalar field is valued in the lie algebra of a Yang-Mills theory. Here, $$D_{\mu}=\partial_{\mu} + [A_{\mu},\Phi],$$ and ...
24. ### Finding the Earth's magnetic field strength using a Galvanometer

Homework Statement [/B] I am working on a experiment on finding the Earth's magnetic field strength in Denmark. Using a Galvanometer and a constant power source of 5.1V and slowly adjusting the resistance, I was able to find the changes in angle in relation to the changes of current. 2...
25. ### B Coil B field strength with different diameters

Hi, I have a quick question. Say I have two metal rods or tubes and I want to make an electromagnet, one rod is with a diameter x and the other rod has a diameter of x2 (two times larger) Now I take the same gauge copper wire and wrap an equal amount of turns around each of the two rods. Then I...
26. ### I Time Dilation: Does Gravitational Field Strength Matter?

Hi I have 2 questions. There are 2 planets and one clock on each of them. One of them has a bigger gravitational field strength. And two clock have same distance from the core. 1-) Does time dilation occur between two? Which clock ticks slower? 2-) If time dilation occurs, which formula...
27. ### A How are curvature and field strength exactly the same?

I am watching these lecture series by Fredric Schuller. [Curvature and torsion on principal bundles - Lec 24 - Frederic Schuller][1] @minute 34:00 In this part he discusses the Lie algebra valued one and two forms on the principal bundle that are pulled back to the base manifold. He shows...
28. ### Field strength tensor for a moving charged particle

Hi, I am studying Chapter14 in Jackson. My attached file is about field strength tensor. My question is how can I obtain the radiation and the non-radiation terms in the field strength tensor for a moving charged particle. Many thanks.
29. ### Calculating Magnetic Field Strength in a Stator DC Motor

Hey, I need a little help I know in a DC motor there are permanent magnet and also coil So my question is, what is the equation to calculate the magnetic field strength in a stator dc motor compound?
30. ### Electric field strength at a point between charges

Find the electric field strength at point B between two charges shown below: Given/Known Values q1 = 4.0×10-6 C r1 = 40 cm = 0.4 m (Distance from q1 to point B) q2 = -1.0×10-6 C r2 = 30 cm = 0.3 m (Distance from q2 to point B) k = 9.0×109 Nm2/C2 Equations Electric Force: FE = (k⋅q1⋅q2)/r2...
31. ### Magnetic field strength at a distance

Hopefully, a simple question with a simple answer. I have a flat magnet (assume infinite long and wide) with a field strength at the surface of (for simplicity) exactly 1Tesla. What will the field strength be (in air) 1mm away from that surface? I know approximates to 1/r^3, but 1/0.001^3 =...
32. ### Calculating electric field strength

Homework Statement A cylinder of radius R= cm 1.2 and length L= 51 cm has a charge Q=2.3 μC spread uniformly along its surface (and not on its flat ends). a) Calculate the electric field strength a distance d=4 mm from the cylinder’s surface (not near either end) b)Calculate the electric...
33. M

### I Will a solenoid inside another solenoid increase its strength?

Will placing a solenoid inside another solenoid increase it's over all strength? While doing research into solenoids I came across the MagLab (The National High Magnetic Field Laboratory) where they place coils one inside another to bolster the field, and reach upwards of 45 Tesla. They use an...
34. C

### Electric field strength between charged plates help

Homework Statement Homework EquationsThe Attempt at a Solution E=kq/d2 how do I involve the kinetic energy K in the equation?
35. C

### Electric field strength between charged plates

Homework Statement Homework EquationsThe Attempt at a Solution E=kq/r2 so when the distance increase E should decrease? I know this is wrong, but can someone explain why? Thanks
36. C

### Electric field strength

Homework Statement Homework EquationsThe Attempt at a Solution I tried to use the formula: F=kq1q2/r2 So at point B, the electric field strength is( 2kQ/r2) - (-kQ/r2)= 3kQ/r2 At A: (2kQ/r2)+(-kQ/r2)=kQ/r2 At C: -(2kQ/r2)-(-kQ/r2)=-kQ/r2 So B is the strongest? Is there an easier way to do it?
37. C

### Magnetic Field Strength

Homework Statement Homework EquationsThe Attempt at a Solution Shouldn't they be the same? Does one being above the current and the other being below make any difference? I know when there is a higher density of magnetic field lines, the magnetic field strength is greater, but in this case...
38. ### Electric field strength on particles of various distances

There is no math in this one! I just wanted to know if I had the idea correct. Homework Statement If I have two positively charged particles at a distance between them that a field is produced between and around them, will test particles that repel away be solely a function of their distance...
39. ### A Field strength measurement and continuity

Something about the theory of quantum measurement/collapse in the case of quantum fields... Suppose I have a field, either a scalar, vector or spinor, that I want to describe as a quantum object. For simplicity let's say that it's a scalar field ##\phi (\mathbf{x})##, where the ##\mathbf{x}## is...
40. ### Calculation of the electric field strength

Hey, First I want to find the electric field strength from the middle between two point charges q1 = 8nC and q2 = -6nC. The distance between the two charges is 10 cm. Then i want to find out at which point of a straight line, which runs through the two charges is the electric field strength...
41. ### Field strength to deflect electron in a cathode-ray tube

Homework Statement An electron in a cathode-ray tube is accelerated through a potential difference of 10 kV, then passes through the d = 2.4-cm-wide region of uniform magnetic field in the figure(Figure 1) . What field strength will deflect the electron by θ = 13 degrees?Homework Equations...
42. ### Calculating Magnetic Field Strength from FFT

Hello All, Briefly on the exposition; I'm an undergraduate assistant to a professor. We contribute to the Muon g-2 experiment in Fermilab, designing and optimizing the magnetic-measurement equipment. As you might imagine I utilize the Fourier Transform often to analyze data. The data I'm...
43. ### Electric field strength inside a conductor

I read on physics.stackexchange that using Gauss Law we can prove that the electric field strength increases as the radius increases inside a metallic conductor. Later on the same website, I encountered a contradicting statement that claimed that inside a conductor, the charges aren't free to...
44. ### A Proof - gauge transformation of yang mills field strength

In Yang-Mills theory, the gauge transformations $$\psi \to (1 \pm i\theta^{a}T^{a}_{\bf R})\psi$$ and $$A^{a}_{\mu} \to A_{\mu}^{a} \pm \partial_{\mu}\theta^{a} \pm f^{abc}A_{\mu}^{b}\theta^{c}$$ induce the gauge transformationF_{\mu\nu}^{a} \to F_{\mu\nu}^{a} -...
45. ### A LSZ formula and Field Strength renormalization factor

Hi all, I have doubts on the role of the Field Strength renormalization ##Z_\psi=1+\delta_\psi## when computing amplitudes. I never did this, maybe because it was not needed before, but i noticed that in the solution of a specific problem, to obtain the correct result, you need to multiply the...
46. ### Electric field strength in an ink-jet printer

Homework Statement One type of ink-jet printer, called an electrostatic ink-jet printer, forms the letters by using deflecting electrodes to steer charged ink drops up and down vertically as the ink jet sweeps horizontally across the page. The ink jet forms 29.0 μm diameter drops of ink...
47. ### Difference Electric Field Strength Point Charges vs. Plates

Why does the electric field strength on a straight line (E = k.(Q1/d12+Q2/d22). D1,2 = distance with respect to Q1,Q2) between two point charges vary with the location on this line while the field strength between two parallel plates which remains the same anywhere between the plates...
48. ### Electric field strength -- calculating distance from charge

Homework Statement At a distance D from a very long (essentially infinite) uniform line of charge, the electric field strength is 1000 N/C. At what distance from the line will the field strength to be 4000 N/C? Homework Equations E=kq/r2 The Attempt at a Solution I know that E is inversely...
49. ### Ligand Field Strength and UV absorbance

I have a lab report for an experiment in which we used ion exchange chromatography to separate three Chromium complexes, CrCl2(OH2)4+, CrCl(OH2)52+, and Cr(OH2)63+ We used a UV vis to find the absorbance of each compound and used that to calculate the mole fraction of each ion in a mixture. One...
50. ### Relationship between emf and magnetic field strength

Homework Statement See image below. Homework Equations motional emf = induced voltage = B L v The Attempt at a Solution I thought the answer would be A since there's a direct relationship between EMF and magnetic field strength. The answer is D.