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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  1. S

    Calculate the electric field strength and the direction on the z-axis resultant

    Homework Statement Calculate the electric field strength and the direction on the z-axis resultant from 3 line charges of blah blah and blah located at (x,y), (x1,y1), (x2,y2) respectively. Homework Equations I assume I just use E = k.Q/r^2 The Attempt at a Solution So I work out...
  2. S

    Magnetic field strength between two wires homework

    Homework Statement Two straight parallel wires are placed vertically on a wall. The distance between the wires is 12 cm and the current through each one is 7.5A. In the left wire the current is directed upwards and in the right one the current points downwards. Determine the magnetic field...
  3. J

    Electric field strength of wire problem

    The electric field strength 5 cm from a very long charged wire is 2000N/C . What is the field strength 10 cm from wire. A)1x10^-4 N/C B)1x10^3 N/C C)9.9x10^7 N/C D) None of these I have E=kq/r^2 and infinite line charge E=(2k\lambda)/R 2000 * .05 m^2 /K =q q=5.56 E-8 k5.56E-8/.^21 m =...
  4. O

    Converting magnetic field strength into a vectorial distance.

    Hey guys, I trying to work out this formula for work. We have a magnetic solenoid that is suspended a certain distance from a sensor tool. This sensor has 3 magnetometers that measure the field strength in Bx,By,Bz directions. The magnetic solenoid is run with a constant current of 0.75A. We...
  5. N

    Question about earth's magnetic field strength

    Does Earth's magnetic field strength increase with depth?
  6. Z

    Electric field strength and potential gradient

    A bit of a problem. My book teaches me that E = -(dV/dx), where E is the electric field strength, V is the electric potential, and x represents displacement. But, it also suggests along with the above formula that E = -(V/d) and displays a circuit with a battery of p.d. V and two parallel...
  7. L

    Solve for Gravitational Field Strength at Point A: Get Help Here!

    Please check the attachment. The question is: Find the gravitational field strength at the point A in terms of G. So I went about assuming we use g = GM/r^2, for both masses, and then subtract them as we're meant to find the overall using vectorial addition. But, the answer in the back...
  8. N

    What is the equation for calculating electric field strength between two plates?

    Homework Statement Two plates each have an area of 80cm2 and are placed facing one another in a vacuum. If the top plate carries a positive charge of 25nC and the bottom plate carrie, a charge of -25nC. Find the electric field strength between them. Permitivity of free space = 8.9 * 10^-12...
  9. R

    Stern Gerlach Gradient Field Strength

    I am trying to recreate the Stern-Gerlach experiment and am having trouble trying to calculate the gradient magnetic field. I am using two magnets with one having a sharp edge and the other flat. I have calculated what the deflection will be of the electron will be in terms of the gradient...
  10. J

    Exploring the Power of a 5 Tesla Magnetic Field | Unveiling the Mystery

    this is just a question i can't seem to find an answer for, but i was wondering how strong a 5 tesla magnetic field is?
  11. S

    Charge vs. Electric Field Strength

    The question in question: "If charge was plotted versus electric field strength; what shape of graph would you get? How would you straighten in? What quantity would the slope of the straightened graph represent?" Related equation: |E|= F/q Ignoring the graphing information, the question...
  12. T

    Distance between two charges where field strength = 0

    [SOLVED] Distance between two charges where field strength = 0 Homework Statement Two particles having charges q1 = 0.500 nC and q2 = 9.00 nC are separated by a distance of 2.00 m. At what point along the line connecting the two charges is the total electric field due to the two charges...
  13. U

    EM wave field strength and energy

    Another noobish question: Let's say there is an electromagnetic wave of constant wavelength and constant peak amplitude that travels a known distance. Let's say that we also know the total energy of this EM wave. Is there some formula that can tell us what the peak value of the electric field is...
  14. H

    Electron Velocity vs Field Strength?

    I have two cathode ray tubes which generate the same amount of beam, i.e., one tube fires off x electrons per second to the screen at velocity m; the other fires off x electrons per second at velocity n. Say m=2n. 1. Is magnetic field FROM BEAMS ALONE the same?? 2. One twice the...
  15. B

    Electric Field Strength charges

    Homework Statement Charge A has 10 electric field lines coming out, Charge B has 20 lines coming out, and Charge C has 30 lines coming in. Which pair of these charges will have the largest force between them if placed one cm apart? Homework Equations The Attempt at a Solution Is...
  16. W

    [101] Magnetic field strength in fN

    [SOLVED] [101] Magnetic field strength in fN Homework Statement You have arranged that the magnetic field in a particular region of space is due North with a value of 0.01 T. An electron enters the field traveling to the West with a speed of 0.05 of the speed of light. As a result, the...
  17. K

    Magnetic field strength needed to lift a heavy conductor

    Homework Statement A heavy conductor (mass m, length l, resistance R) is suspended by two springs each with spring constant k, and connected to a battery with electric potential V as shown in the figure. A magnetic field B is now imposed. The acceleration of gravity is 9.8 m/s^2. I'm going to...
  18. X

    Coursework - Gravitational Field Strength

    Homework Statement Okay so, we weren't given much of a question other than "Prove the Earth's GFS is 9.81 N/KG" So what I'm asking is, with the data that I have collected, is how I go about doing this? As it stand we set up an experiment with the ticker tape machine, rolled the little buggy...
  19. M

    Field strength and energy of electrons in a magnetron

    Homework Statement The microwaves in a microwave oven are produced in a special tube called a magnetron. The electrons orbit the magnetic field at 2.4 GHz, and as they do so they emit 2.4 GHz electromagnetic waves. a) what is the magnetic field strength? b) if the maximum diameter of...
  20. A

    Electric field strength from a light bulb

    Homework Statement What is the approximate electric field strength of the electromagnetic waves radiated by a 100-W light bulb, measured 3.0m from the bulb? Homework Equations $$\vec{E}=\frac{kq}{d^{2}}$$ $$P=\frac{2kq^{2}a^{2}}{3c^{3}}$$ The Attempt at a Solution I solved for...
  21. V

    Is Direction Considered in Determining Resultant Electric Field Strength?

    How do I know that the resultant filed strength acts toward Y? Thank you
  22. J

    Calculating Electric Field Strength between Charges

    Homework Statement q=4.0x10^-6C, 8.0x10^-6C d=2m Homework Equations Two charges of +4.0x10^-6 C and +8.0x10^-6C are placed 2.0m apart. What is the field strength halfway between them? The Attempt at a Solution netEa= (9.0x10^9)(4.0x10^-6C) + (9.0x10^9)(8.0x10^-6C)...
  23. M

    Electric field strength and speed

    The electric field strength is 1.70×104 inside a parallel-plate capacitor with a 1.40 spacing. An electron is released from rest at the negative plate. What is the electron's speed when it reaches the positive plate? Help please...
  24. C

    What electric field strength will cause the bead to hang suspended in the air?

    1. A 0.180g plastic bead is charged by the addition of 0.700 x 10^10 excess electrons. What electric field strength will cause the bead to hang suspended in the air? 2. Is amount of excess electrons the exact same as the charge of the bead?? 3. I am sure you use F=qE. But I am...
  25. M

    Calculating Electric Field Strength to Stop an Electron

    Homework Statement An electron moving to the right at 3% the speed of light enters a uniform electric field parallel to its direction of motion. The electron is to be brought to rest in the space of 6.0cm. What is the strength of the field?______N/C Homework Equations F = q * E The...
  26. S

    Calculating Magnetic Field Strength for Parallel-Plate Capacitor

    Homework Statement A 10-cm-diameter parallel-plate capacitor has a 1.0 mm spacing. The electric field between the plates is increasing at the rate 1*10^6V/m/s. What is the magnetic field strength 3.0 cm from the axis? Homework Equations B= uo/(2*pi) *r/R^2*(Chang in Q/ change in...
  27. L

    What Does the Slope Represent in a Voltage vs. Distance Graph?

    Well I have this lab on electric field lab and what I did was measure the voltage from different distances on a parallel plate. So when I plotted the graph Voltae vs. Distance, I got a linear line and the equation was y = 85x (somewhat like that disregarding the y-intercept). My concern is what...
  28. P

    Electric Field Strength at Point Z

    what are the magnitude and direction of the electrical field strength at point Z in the situation below? negatively charged sphere, x(-2.0*10-5C) is left most, 60 cm to the right of it is a positively charged sphere,Y (8.0*10-6C). Point Z is 30 cm to the right of Y. What I did: First i...
  29. J

    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 = 6.371 103 km. __________ km (b) Find the altitude above the Earth's surface where Earth's gravitational field strength...
  30. P

    Electric Field Strength from point charges

    Question Charges at three corners of a square are shown in Figure P26.34, in which n = 9. To answer the following questions, use the letters k, Q, q, L, and m. IMAGE IS LOCATED HERE: http://www.webassign.net/knight/p26-34.gif a) Write the electric field at point P in component form. b)A...
  31. B

    Magnetic Field strength Problem

    Homework Statement What are the magnetic field strength and direction at the dot in Figure Ex32.8, in which v = 3.0*10^7 m/s? Figure Ex.32.8 is attached to the this post. r = 0.02828 m m0/4pi = 10^-7 T v = 3.0*10^7 m/s q = 1.60217653*10^-19 C Homework Equations Biot-Savart Law...
  32. K

    Measuring dB Level: Receiver or Field Strength Meter?

    can anyone describe wat is dB level. can dB level be showed through receiver or field strength meter? thx for helping
  33. H

    What is the Magnetic Field Strength of a Magnetron at a Resonant Frequency?

    Homework Statement A magnetron is a microwave source in which a "bunch" of electrons travel on a circular orbit in a uniform magnetic field. As the electrons pass the electrodes, a high-frequency alternating voltage difference occurs. Suppose the resonant frequency is f = 2.82×10^10 s-1...
  34. P

    Why does magnetic field strength decrease faster than gravity at a distance?

    why does magnetic field strength decrease much faster than the inverse square of the distance like gravity? Is it because the force lines have to curve back to the source? Is magnetism also carried by an "imaginary" particle? Thanks. Mr Beh
  35. F

    [3-in-1] Radioactivity detection, Lightning & Magnetic field strength

    1) Methods/equipment for radioactivity detection. For my high-school Chemistry studies, needs clarification. Geiger counter: A small chamber contains a high voltage electric field inside filled with inert gas. When ionizing particles/radiation enters the chamber, it will ionise the...
  36. D

    What is the maximum magnetic field strength?

    Homework Statement The figure shows a vertically polarized radio wave of frequency 1.0 times 10^6 traveling into the page. The maximum electric field strength is 1000V/m. What is the maximum magnetic field strength? What is the magnetic field strength at a point where E=500V/m down What is...
  37. D

    Magnetic field strength quick question

    Homework Statement Two very long parallel wires which are 20cm apart ,carry currents of 1.5A and 2.0A respectively, flowing in opposite directions. Calculate the magnetic field strength at following points in plane of two wires (i) midway between wires (ii)at a point 10cm from the wire...
  38. R

    Initial electric field strength

    Homework Statement The initial electric field strength between oppositely charged parallel plates is 3.0 X 10^3 N/C, what would the electric field strength become if half of the charge were removed from each plate and the separation of the plates were changed from 12 mm to 8 mm? Homework...
  39. A

    Magnetic field strength against current

    Homework Statement Hi after doing a experiment at school, I have come up with a graph of magnetic field strength against current. I was wondering if anyone knew what the gradent of this line or area under the line represented? Homework Equations B=KI/R? The Attempt at a Solution...
  40. M

    What is the electric field strength at the center of the triangle?

    Homework Statement What is the electric field strength at the center of the triangle? Three 13.0 -cm-long rods form an equilateral triangle. Two of the rods are charged to + 19.0 nC, the third to - 19.0 nC . What is the electric field strength at the center of the triangle...
  41. D

    Magnetic field strength and SHM

    Homework Statement Hi there.this is one of those proof dealies that i think i nearly have right but i was wondering if anyone could point out if i have made too many assumptions or anything thanks. Show that if a bar magnet is suspended in a uniform magnetic field, of strength H, and is...
  42. C

    Confused about electric field strength and PE

    I have just started to learn these things(electric field strength, electric potnential energy and electric potential). I am not very clear about what they are. I would like to ask a few questions here. Why is electric field strength somtimes +ve but sometimes -ve? what does each of them...
  43. N

    Yang-Mills Field Strength Tensor

    I was wondering why for [tex] F_{\mu \nu} = [D_{\mu},D_{\nu}] = \partial_{\mu}A_{\nu}-\partial_{\nu}A_{\mu}+[A_{\mu},A_{\nu}] [\tex] the term [tex] A_{\mu}\partial_{\nu} - A_{\nu}\partial_{\mu} [\tex] vanishes.
  44. U

    Electric Field Strength H Units - Ampere Turns/Meter?

    What are the units of the electric field strength H? I know that H = NI/L for a solenoid and I'm wondering if there is any condensed unit or if it is just ampere turns per meter.
  45. A

    Electric field strength in a square.

    Hi guys, Suppose I have a point O in the centre of the square (of side length X), where the top 2 corners of the square carries a positive charge each and the bottom left corner a negative charge and the bottom right corner a positive charge, what would the magnitude and direction of the...
  46. Astronuc

    What is maximum magnetic field strength of SC magnet

    Another poster is looking for a 20T magnetic field or better, so I went looking for what has been reported as the maximum field strength for an SC magnetic field to date. However I found some contradicting claims. Is there a refereeing organization or a reputable source from which to...
  47. S

    Calculate the gravitational field strength

    From the radius (1740 km) and mass (7.36 X 10^22 kg) of the moon, calculate gravitational field strength for this body. g = F/m = F/(7.36X10^22 kg) F = GmM/r^2 = (6.67X10^-11)(7.36X10^22)M/(1740X10^3)^2 What is the big M?
  48. Mk

    After a certain external field strength Diamagnetism can collapse?

    After a certain external field strength can it collapse?
  49. Mk

    Maxiumum magnetic field strength

    The maximum theoretical field strength for a neutron star, and therefore for any known phenomenon is 1013 T. Why is there a maximum?
  50. D

    Calculating Electric field strength

    Alright everyone, normally I am prett good with electrostatics, butlately...I've been in a serious rut. My physics professor has asked us to varify the electric field at a distance r from a cylindrical gaussian surface, under three conditions. 1) with a constant chrage density, 2) with a...
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