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.

View More On Wikipedia.org
Recent contents Top users
  1. G

    Measuring Electric Field Strength

    I have to construct an experiment which measures the electric field strength at various distances from a charged Van Der Graaff generator. How would i go about this?
  2. S

    Combined gravitational field strength

    Homework Statement 2 masses, 5k and 10kg are fixed in place at the coordinates 1,0 and 1,1 respectively. what combined gravitational field strength do they produce at the point 0,0? Homework Equations g = GM/r^2 The Attempt at a Solution total g = G(5)/(1)^2 +G(5)/2 not the right answer...
  3. D

    Calculating electric field strength

    Homework Statement http://img219.imageshack.us/img219/3310/problemi.png Homework Equations F = kq/r^2 The Attempt at a Solution O ----- x ----O -----------O Let the electric field of the first O be E1, second be E2, third be E3. RED - .02m BLUE - .016m GREEN - .033m E1...
  4. L

    Estimating electric field strength

    1. Estimate the electric field (strength and direction) at the point A. 5cmx5cm gridL 2. E = -dV/ds 3. I had four options, each a combination of 500 or 1000V/m for the E field strength and then left or right for the direction. I knew it must be to the left because the field...
  5. A

    Calculating Magnetic Field Strength for Sodium Zeeman Splitting

    Homework Statement Estimate the strength of the magnetic field for which Zeeman splitting of the 3p energy levels in sodium equals the energy due to spin-orbit coupling Homework Equations The Attempt at a Solution I know the equations for spin orbit and the zeeman effect, and I...
  6. G

    Calculating Magnetic Field Strength and Direction in a Multi-Wire System

    please help?? 1. Homework Statement I got 1/2 of this problem right, but I am not sure of the other part. I have attached the picture. The questions are as follows (with the answers that I am sure of) -- What is the magnetic field strength at point 1 in the figure? What is the magnetic...
  7. G

    Calculating Magnetic Field Strength and Direction in a Two-Wire System

    Homework Statement I got 1/2 of this problem right, but I am not sure of the other part. I have attached the picture. The questions are as follows (with the answers that I am sure of) -- What is the magnetic field strength at point 1 in the figure? What is the magnetic field direction at...
  8. Z

    Gravitational field strength at latitude

    This figure is captured from my physics textbook and it is about the gravity at latitude http://pix.gogobox.com.tw/out.php?i=567045_.JPG I want to know the difference between mg0 and mg(theta). Which one is the weight of the object? Thank you!
  9. S

    Magnetic Field Strength (Integral needed)

    Homework Statement You have 10 m of 0.55 mm diameter copper wire and a battery capable of passing 13 A through the wire. What magnetic field strength could you obtain inside a 2.8 cm diameter solenoid wound with the wire as closely spaced as possible? Homework Equations Turns of a...
  10. D

    What is the force between two magnets with different magnetic field strengths?

    Homework Statement Magnet A has twice the magnetic field strength of magnet B and at a certain distance pulls on magnet B with a force of 55 N. With how much force, then, does magnet B pull on magnet A? Homework Equations unknown The Attempt at a Solution unknown
  11. V

    Magnetic field strength between two wires

    wire 1 has a current of 1A directed into the page, wire 2 is 20 cm to the right of wire 1 with a current of 1A, what direction does this current have to flow in order for the magnetic field strength at the mid point between them to be non zero ? from the right hand rule the mag field from...
  12. A

    Exploring the Relationship between Electric Field Strength & Potential Gradient

    Homework Statement What is the relationship between electric field strength and the potential gradient? Homework Equations The Attempt at a Solution This is my Calc based Physcis lab question but I am at a total loss. I do not understand what potential gradient is in the...
  13. JJBladester

    Limit Problem - Electric field strength of an infinite line of charge

    Limit Problem --- Electric field strength of an infinite line of charge Homework Statement What is the limit of the following equation? Homework Equations \stackrel{lim}{L\rightarrow\infty} \frac{K|Q|}{r\sqrt{r^{2}+(L/2)^{2}}} The Attempt at a Solution The book gives an answer...
  14. P

    Electric field strength of a wire comparison

    1. Homework Statement The electric field strength 7.79 cm from a very long charged wire is 2660 N/C. What is the electric field strength (in N/C) 12.7 cm from the wire? 2. Homework Equations E= (9*10^9) Q/ r^2 3. The Attempt at a Solution i have energy. so is tried to solve...
  15. K

    Calculating Electric Field Strength from a Charged Wire

    Homework Statement The electric field strength 8.05 cm from a very long charged wire is 1310 N/C. What is the electric field strength (in N/C) 30.0 cm from the wire? Homework Equations E=F/Q E=KQ/R^2 The Attempt at a Solution First I try to find the charge using E=KQ/R^2...
  16. G

    Parallel Plate Capacitor: Electric field strength, flux & magnetic field

    Homework Statement This is a question on a past paper of a second-year undergraduate physics paper. A parallel plate capacitor is charged and the voltage increases at a rate of dV/dt. The plate radius is R and the distance between the plates is d. (a) What is the electric field...
  17. R

    Is Object A Positive and Object B Negative Based on Electric Field Direction?

    It is not a homework problem, thought it can kinda be. But when they show you a diagram with object A and B, If the electric field point towards A and away from B. Does that mean that A is + and B is -?
  18. M

    Calculating the voltage and electric field strength between two parallel plates

    Homework Statement - How much is the electrical voltage U between two evenly electrified parallel flat plates, distanced d = 1 cm, if the strength of electric field between them is E = 1 V / m? - - What is the strength of electric field to the left and to the right of each plate? - What is...
  19. R

    Calculating Electric Field Strength of Three Point Charges - Convert to V/m

    Hey i worked out this answer for the electric field strength at a point due to three point charges. E = -46736i + 46736j -39546k How do i convert this to V/m? eg. 12345 V/m I have checked everywhere Thanks for any help
  20. H

    Electric field strength before reaching the state of electrostatic equilibrium

    Homework Statement In such a picture, http://i1021.photobucket.com/albums/af335/hectoryx/electrostaticequilibrium_1.jpg Induced charges will emergence on the left and right side of non-perfect conductor B, because the effect of the electric field of conductor A. As is known to all, when...
  21. C

    Electric Field Strength- variations

    If the electric field lines are curved as opposed to straight, say from straight parallel lines parabolic curves develop, would there be any change in the field strength? ie would it be stronger when the lines are parallel than when they curve?
  22. J

    Magnetic field strength and distance

    Gravitational force is divided by distance squared. What is the equivalent divisor for a fixed bar magnet? Thank you for your kind attention :-) (-_-)
  23. T

    What is the magnetic field strength on Earth's surface at either pole?

    Homework Statement What is the magnetic field strength on Earth's surface at either pole? Earth's magnetic dipole moment is D_0 What is the magnetic field strength on Earth's surface at either pole? B = ____ G Homework Equations _u = NIA ; N is the number of turns I is current, A...
  24. M

    Time dilation b/c of Gravitaional field strength

    Can gravitational field strength cause time dilation. as G.F.S on Earth is 10 N/kg and on moon it is 1.6 N/kg. so will a clock on the moon surface tick slowly for the observer on Earth or not?
  25. N

    What is the maximum magnetic field strength of a micro-electromagnet?

    Hi all, I was wondering if anyone knew, or if anyone knows where I can find, the maximum magnetic field that a micro - electromagnet can put off... I am sure this depends on a lot (thermal degredation, materal properties etc) but I just need an estimation as I am running a simulation and need a...
  26. H

    What is the field strength of a pulse in an air core coil?

    I'm new to the forum, so hello! How can i calculate the magnetic field strength of the pulse of an air core coil, the number of turns is 20 & the height of the coil is 20mm, not single or multi layered just random wound. The pulse is 10V & 1Amp, the Inductance is 200uH. Not sure how to go...
  27. M

    Creating a Degausser to Reduce Magnetic Field Strength

    I have a component made of some sort of stamped steel which has a significant magnetic field (upto 2000mGa) which I need to use near a sensitive magnetic sensor. The field is high enough to saturate the sensor so I can't calibrate it out. Does anyone have any idea about degaussing? I tried...
  28. S

    Question about Electric Field Strength and Electric Potential

    Lets say I have a point charge X placed on a region between a +Q test charge and +2Q point charge where electric field strength is zero. Since E=-dV/dR, does it mean V=0 or constant? Can the point charge move if i place it there? Well let's just ignore gravitational field/force here.
  29. P

    EM Field strength and plane waves

    Hi ! I've a question. Where is the connection between the (kinetic) Lagrangian - \dfrac{1}{4} F_{\mu \nu} F^{\mu \nu} and a plane wave of the form \vec{\varepsilon} exp(i \vec{k} \cdot \vec{x}) / \sqrt{V} (the epsilon is a polarization vector) confined in a box with a finite volume V ? I...
  30. D

    Potential difference to find the magnitude of the electric field strength

    what are the components to find the magnitude of the electric field strength when only potential difference and that there are two oppositely charged plates that are separated by a given distance.
  31. W

    Finding the field strength of an EF

    Homework Statement A square, with charges at each corner. The upper left (1) has a charge of +q. The upper right (2) has a charge of -2q. The bottom right (3) has a charge of +2q. The bottom left (4) has a charge of -q. The square has side length a. a = 5.20 cm and q = 11.8 nC Find...
  32. M

    Linearly polarized light and its field strength.

    Homework Statement if linearly polarized light has an electric field strength E, what is its field strength after it has passed through polarizing material that has a transmission axis oriented at an angle theta relative to the direction of E? Homework Equations none.The Attempt at a Solution...
  33. A

    Gravatational Field Strength problem (Grade 12 physics)

    Homework Statement The gravitational field strength of an unknown planet is 15.5 N/kg on its surface. Calculate the value of “g” if the planets mass and radius were both doubled. Hint: Use variation. Homework Equations g= GM /R2 The Attempt at a Solution Well my teacher gave a...
  34. E

    Second-Order Field Strength Energy Spectrum of Spherical Shell

    what the energy spectrum to second order in the field strength for a spherical shell?
  35. R

    What is the electric field strength?

    Homework Statement 50 pJ of energy is stored in a 2.0 cm*2.0 cm*2.0 cm region of uniform electric field. What is the electric field strength? Homework Equations not sure The Attempt at a Solution not sure how to start this problem
  36. A

    What is the field strength and when does a situation like this occur?

    Please help me with the following: What is the field strength needed to achieve a current density of 5 x10^4 [Am^-2] in a conductor of resistivity 5 x 10^-8 [Ω m] The answer I got was 2.5 x 10^-3 N C^-1 using the equation J = σ E But then I was wondering when a situation like this occurs and...
  37. L

    Change in gravitational field strength

    Homework Statement The tallest spot on Earth is Mt. Everest. But another well-known mountain is the Mont Blanc, European Alps, which is 4807 m above sea level. If the radius of the Earth to sea level is 6367 km, how much does the gravitational field strength change between the sea level value...
  38. C

    Finding magnitude of electric field strength

    Homework Statement Consider three charges arranged as shown. What is the magnitude of the electric field strength at a point 2.7 cm to the left of the middle charge? The value of the Coulomb constant is 8.98755 × 109 N · m2/C2 . Answer in units of N/C. Homework Equations I'm truly...
  39. P

    Peskin Schröder Chapter 7.1 Field Strength Renormalization

    Hello, I read chapter 7.1 of "An Introduction to Quantum Field Theory" by Peskin and Schröder and have two questions. They derive the two point function for the interacting case. On page 213 they manipulate the matrix element, after insertion of the complete set of eigenstates. <\Omega...
  40. N

    How Do You Calculate Electrical Field Strength in Kapton Insulated Cables?

    Dear All, How do i calculate the Electrical field strength in v/mm for a Kapton Insulated Cable. Conductor AWG 24/19 - 0,6 mm Kapton wall thickness : 1,0 mm Voltage : 15 KV Thanks.
  41. A

    Two spheres, solve for electric field strength

    Homework Statement Two 2.0-cm-diameter insulating spheres have a 6.50 cm space between them. One sphere is charged to + 89.0 nC, the other to - 95.0 nC. What is the electric field strength at the midpoint between the two spheres? Homework Equations Esphere = KQ/r^2 k = 8.99 * 10^9...
  42. matt_crouch

    Gravitational Field Strength Calculations with a Pendulum

    As a pendulum can be used to calculate the gravitational field strength by using the equation Time period= 2(pi) sqrt (length/g) this equation assumes that the pendulum bob is moving in Simple harmonic motion. However at very small lengths the pendulum bob tends to move in a more...
  43. F

    Gravitational Field Strength of Space Station w/ N Astronauts

    Homework Statement A space station consists of two living modules attached to a central hub on opposite sides of the hub by long corridors of equal length. Each living module contains N astronauts of equal mass. The mass of the space station is negligible compared to the mass of the astronauts...
  44. X

    Field strength giving rise to a polarization charge of -s.cos(theta) on a cavity

    Hello, I'm learning EM from Bleaney & Bleaney and got stuck on Ex2.1 (can do Ex2.2-2.7, though...) - If the polarization charge on the surface of a spherical cavity is -s.cos(theta), prove that the field strength at the centre is s/3e0. If I expand V(r) within the cavity as A.r.cos(theta) +...
  45. U

    Solving for Magnetic Field Strength given Induced voltage in a coil

    Homework Statement This is part of a lab I did, I am working on the writeup now. We placed a coil of wire inside of a Helmholtz pair, with 20V of 60Hz AC through the Helmholtz pair. The coil inside was connected to an oscilloscope and the induced voltages were recorded. I now need to...
  46. H

    Magnetron Electron Field Strength

    Homework Statement Suppose the resonant frequency is f = 1.47×1010 s−1; that is, the electron period of revolution is T = 6.80×10-11 s. What is the corresponding strength of the magnetic field? Homework Equations qvb=mv2/r qb=mv/r The Attempt at a Solution 1.6E-19*b=9.1E-31*v/r...
  47. S

    Gravitational Field Strength Help

    Hello Everyone, I've been trying to get the answer to this problem for ages now and I just can't match my answer with the one in the back of the textbook. I hope you can let me know what I'm doing wrong. Homework Statement What is the gravitational field strength at a place 220 km above...
  48. F

    Find the electric field strength inside a solid sphere.

    Homework Statement A solid sphere 25cm in radius carries 14uC, distributed uniformly throughout its volume. Find the electric field strength (a.) 15cm, (b.) 25cm, (c.) 50cm from the sphere's center. R = .25m Q = 14 * 10^-6 C Homework Equations p = q/(volume) E = (kq)/r^2 The...
  49. D

    Earth's gravitational field strength

    Homework Statement (a) Find the altitude above the Earth's surface where Earth's gravitational field strength would be two-thirds of its value at the surface. Assume re = 6.371 multiplied by 10^3 km. wrong check mark km (b) Find the altitude above the Earth's surface where Earth's gravitational...
  50. N

    Defining Flux in the Context of Electric Fields

    A 124 cm diameter loop is rotated in a uniform electric field until the position of the maximum electric flux is found. The flux in this position is measured to be 6.33 x 105. What is the electric field strength?
Back
Top