VIDEOS 1 TO 50

Electric Fields: Crash Course Physics #26

Published: 2016/10/07

Channel: CrashCourse

Electric field | Electric charge, electric force, and voltage | Physics | Khan Academy

Published: 2008/05/13

Channel: Khan Academy

Physics - The Electric Field (1 of 16)

Published: 2013/02/18

Channel: Michel van Biezen

MGMT - Electric Feel

Published: 2009/10/25

Channel: MGMTVEVO

Electric Field, An Explanation

Published: 2014/02/12

Channel: Step-by-Step Science

Electric Field Physics Problems - Point Charges, Tension Force, Conductors, Square & Triangle

Published: 2016/09/21

Channel: The Organic Chemistry Tutor

Electric Field Lines and Properties | video in HINDI

Published: 2017/03/29

Channel: EduPoint

10 Ways to SEE the ELECTRIC FIELD - Part 1

Published: 2014/06/29

Channel: James Lincoln

2. Electric Fields

Published: 2011/03/22

Channel: YaleCourses

Electric Fields

Published: 2010/09/09

Channel: Brightstorm

Physics 12.3.2a - The Electric Field Around a Charge

Published: 2009/04/05

Channel: Derek Owens

Introduction to Electric Fields

Published: 2016/07/31

Channel: Up and Atom

Definition of Electric Field.mp4

Published: 2012/02/17

Channel: Graham Best

Electric Field Strength

Published: 2014/06/26

Channel: Bozeman Science

XII-1.08 Pradeep Kshetrapal Physics.(2014) ELECTRIC-FIELD.Introduction

Published: 2014/04/22

Channel: Pradeep Kshetrapal

Coulomb's Law and Electric Fields.

Published: 2009/11/30

Channel: lasseviren1

Electric Charge and Electric Field Part 1

Published: 2014/07/19

Channel: Matt Anderson

Electric Field Intensity | video in HINDI | EduPoint

Published: 2017/03/19

Channel: EduPoint

ELECTRIC FIELD Visualized with Crystals

Published: 2014/03/19

Channel: James Lincoln

Electric field definition | Electric charge, field, and potential | Physics | Khan Academy

Published: 2016/07/29

Channel: Khan Academy Physics

Electric Field: Calculating the Magnitude and Direction of the Electric Field

Published: 2014/02/12

Channel: Step-by-Step Science

4. Electric Field (Hindi)

Published: 2016/11/28

Channel: Ignited Minds

Physics - The Electric Field (4 of 16)

Published: 2013/02/18

Channel: Michel van Biezen

Electric Force

Published: 2014/06/24

Channel: Bozeman Science

Electric Fields and Electric Field Lines

Published: 2015/07/19

Channel: Animations for Physics and Astronomy

Lec 02: Electric Field and Dipoles | 8.02 Electricity and Magnetism, Spring 2002 (Walter Lewin)

Published: 2014/12/10

Channel: For the Allure of Physics

Electric Fields - A Level Physics

Published: 2012/03/19

Channel: DrPhysicsA

Physics - E&M: Electric Field (8 of 16) Ring of Charge

Published: 2014/03/22

Channel: Michel van Biezen

Electric Field

Published: 2013/11/13

Channel: AK LECTURES

Electric field patterns

Published: 2011/08/31

Channel: Carmel Azzopardi

Physics - E&M: Electric Field (5 of 16) The Electric Dipole

Published: 2014/03/22

Channel: Michel van Biezen

Electric Field at a point on Equitorial Plane of an Electric Dipole video in HINDI EduPoint

Published: 2017/01/23

Channel: EduPoint

Physics Electric Charges & Fields part 25 (Electric field axial point due to diapole) CBSE class 12

Published: 2012/06/03

Channel: ExamFear Education

An electric field given by pierces the gaussian cube

Published: 2016/07/08

Channel: WNY Tutor

What is electric field in Hindi?

Published: 2016/10/23

Channel: Vidya trans

XII-1-6 Electric field Intro (2016)Pradeep Kshetrapal Physics

Published: 2016/04/11

Channel: Pradeep Kshetrapal

Physics: Electric field and electric force (1)

Published: 2010/02/12

Channel: freelanceteach

Electric Potential and Electric Field Intensity - the relation | video in HINDI | हिंदी

Published: 2016/04/16

Channel: EduPoint

Hewitt-Drew-it! PHYSICS 89. Electric Fields

Published: 2013/07/28

Channel: mellenstei

Physics 12.4.3a - Voltage Electric Fields and Distance

Published: 2009/04/05

Channel: Derek Owens

Electric Field at any point due to an Electric Dipole video in HINDI

Published: 2017/04/07

Channel: EduPoint

Physics - The Electric Field (3 of 16)

Published: 2013/02/18

Channel: Michel van Biezen

Physics Electric Charges & Fields part 26 (Electric field equatorial due to diapole) CBSE class 12

Published: 2012/06/03

Channel: ExamFear Education

Electric Field Lines, Dipole, Point Charges, Parallel Plates, & Spherical Conductor, Physics

Published: 2017/01/07

Channel: The Organic Chemistry Tutor

XII-4-03 Motion of charge in electric field (2016) Pradeep Kshetrapal Physics

Published: 2016/06/01

Channel: Pradeep Kshetrapal

The Electric Field Due to a Ring of Charge

Published: 2009/12/01

Channel: lasseviren1

Application of Gauss' Theorem - Electric Field near Charged Infinite Sheet | in HINDI | EduPoint

Published: 2017/02/11

Channel: EduPoint

Bill Doyle: Treating cancer with electric fields

Published: 2012/01/31

Channel: TED

JEE Main Physics- Basic Problems On Electric Field And Electric Potential

Published: 2014/04/04

Channel: sardanatutorials

Lecture-4-Electric Field

Published: 2007/12/07

Channel: nptelhrd

From Wikipedia, the free encyclopedia

This article needs additional citations for verification. (December 2014) (Learn how and when to remove this template message) |

An **electric field** is a vector field that associates to each point in space the Coulomb force that would be experienced per unit of electric charge, by an infinitesimal test charge at that point.^{[1]} Electric fields are created by electric charges and can be induced by time-varying magnetic fields. The electric field combines with the magnetic field to form the electromagnetic field.

The electric field, , at a given point is defined as the (vector) force, , that would be exerted on a stationary test particle of unit charge by electromagnetic forces (i.e. the Lorentz force). A particle of charge would be subject to a force .

Its SI units are newtons per coulomb (N⋅C^{−1}) or, equivalently, volts per metre (V⋅m^{−1}), which in terms of SI base units are kg⋅m⋅s^{−3}⋅A^{−1}.

Electric fields are caused by electric charges or varying magnetic fields. The former effect is described by Gauss's law, the latter by Faraday's law of induction, which together are enough to define the behavior of the electric field as a function of charge repartition and magnetic field. However, since the magnetic field is described as a function of electric field, the equations of both fields are coupled and together form Maxwell's equations that describe both fields as a function of charges and currents.

In the special case of a steady state (stationary charges and currents), the Maxwell-Faraday inductive effect disappears. The resulting two equations (Gauss's law and Faraday's law with no induction term ), taken together, are equivalent to Coulomb's law, written as for a charge density ( denotes the position in space). Notice that , the permittivity of vacuum, must be substituted if charges are considered in non-empty media.

The equations of electromagnetism are best described in a continuous description. However, charges are sometimes best described as discrete points; for example, some models may describe electrons as point sources where charge density is infinite on an infinitesimal section of space.

A charge located at can be described mathematically as a charge density , where the Dirac delta function (in three dimensions) is used. Conversely, a charge distribution can be approximated by many small point charges.

Electric fields satisfy the superposition principle, because Maxwell's equations are linear. As a result, if and are the electric fields resulting from distribution of charges and , a distribution of charges will create an electric field ; for instance, Coulomb's law is linear in charge density as well.

This principle is useful to calculate the field created by multiple point charges. If charges are stationary in space at , in the absence of currents, the superposition principle proves that the resulting field is the sum of fields generated by each particle as described by Coulomb's law:

Electrostatic fields are **E**-fields which do not change with time, which happens when charges and currents are stationary. In that case, Coulomb's law fully describes the field.

If a system is static, such that magnetic fields are not time-varying, then by Faraday's law, the electric field is curl-free. In this case, one can define an electric potential, that is, a function such that .^{[2]} This is analogous to the gravitational potential.

Coulomb's law, which describes the interaction of electric charges:

is similar to Newton's law of universal gravitation:

(where ).

This suggests similarities between the electric field **E** and the gravitational field **g**, or their associated potentials. Mass is sometimes called "gravitational charge" because of that similarity.^{[citation needed]}

Electrostatic and gravitational forces both are central, conservative and obey an inverse-square law.

A uniform field is one in which the electric field is constant at every point. It can be approximated by placing two conducting plates parallel to each other and maintaining a voltage (potential difference) between them; it is only an approximation because of boundary effects (near the edge of the planes, electric field is distorted because the plane does not continue). Assuming infinite planes, the magnitude of the electric field *E* is:

where Δ*ϕ* is the potential difference between the plates and *d* is the distance separating the plates. The negative sign arises as positive charges repel, so a positive charge will experience a force away from the positively charged plate, in the opposite direction to that in which the voltage increases. In micro- and nano-applications, for instance in relation to semiconductors, a typical magnitude of an electric field is in the order of ^{6} V⋅m^{−1}, achieved by applying a voltage of the order of 1 volt between conductors spaced 1 µm apart. 10

Electrodynamic fields are **E**-fields which do change with time, for instance when charges are in motion.

The electric field cannot be described independently of the magnetic field in that case. If **A** is the magnetic vector potential, defined so that , one can still define an electric potential such that:

One can recover Faraday's law of induction by taking the curl of that equation

^{[3]}

which justifies, a posteriori, the previous form for **E**.

The total energy per unit volume stored by the electromagnetic field is^{[4]}

where *ε* is the permittivity of the medium in which the field exists, its magnetic permeability, and **E** and **B** are the electric and magnetic field vectors.

As **E** and **B** fields are coupled, it would be misleading to split this expression into "electric" and "magnetic" contributions. However, in the steady-state case, the fields are no longer coupled (see Maxwell's equations). It makes sense in that case to compute the electrostatic energy per unit volume:

The total energy *U* stored in the electric field in a given volume *V* is therefore

In the presence of matter, it is helpful in electromagnetism to extend the notion of the electric field into three vector fields, rather than just one:^{[5]}

where **P** is the electric polarization – the volume density of electric dipole moments, and **D** is the electric displacement field. Since **E** and **P** are defined separately, this equation can be used to define **D**. The physical interpretation of **D** is not as clear as **E** (effectively the field applied to the material) or **P** (induced field due to the dipoles in the material), but still serves as a convenient mathematical simplification, since Maxwell's equations can be simplified in terms of free charges and currents.

The **E** and **D** fields are related by the permittivity of the material, *ε*.^{[6]}^{[5]}

For linear, homogeneous, isotropic materials **E** and **D** are proportional and constant throughout the region, there is no position dependence: For inhomogeneous materials, there is a position dependence throughout the material:

For anisotropic materials the **E** and **D** fields are not parallel, and so **E** and **D** are related by the permittivity tensor (a 2nd order tensor field), in component form:

For non-linear media, **E** and **D** are not proportional. Materials can have varying extents of linearity, homogeneity and isotropy.

- Classical electromagnetism
- Field strength
- Signal strength in telecommunications
- Magnetism
- Teltron tube
- Teledeltos, a conductive paper that may be used as a simple analog computer for modelling fields

**^**Richard Feynman (1970).*The Feynman Lectures on Physics Vol II*. Addison Wesley Longman. ISBN 978-0-201-02115-8.**^**gwrowe (8 October 2011). "Curl & Potential in Electrostatics".*physicspages.com*. Retrieved 21 January 2017.**^**Huray, Paul G. (2009).*Maxwell's Equations*. Wiley-IEEE. p. 205. ISBN 0-470-54276-4.**^**Introduction to Electrodynamics (3rd Edition), D.J. Griffiths, Pearson Education, Dorling Kindersley, 2007, ISBN 81-7758-293-3- ^
^{a}^{b}Electromagnetism (2nd Edition), I.S. Grant, W.R. Phillips, Manchester Physics, John Wiley & Sons, 2008, ISBN 978-0-471-92712-9 **^***Electricity and Modern Physics (2nd Edition)*, G.A.G. Bennet, Edward Arnold (UK), 1974, ISBN 0-7131-2459-8

This article's use of external links may not follow Wikipedia's policies or guidelines. (January 2017) (Learn how and when to remove this template message) |

- Electric field in "Electricity and Magnetism", R Nave – Hyperphysics, Georgia State University
- 'Gauss's Law' – Chapter 24 of Frank Wolfs's lectures at University of Rochester
- 'The Electric Field' – Chapter 23 of Frank Wolfs's lectures at University of Rochester
- MovingCharge.html – An applet that shows the electric field of a moving point charge
- Fields – a chapter from an online textbook
- Learning by Simulations Interactive simulation of an electric field of up to four point charges
- Java simulations of electrostatics in 2-D and 3-D
- Interactive Flash simulation picturing the electric field of user-defined or preselected sets of point charges by field vectors, field lines, or equipotential lines. Author: David Chappell

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