BlogNCERTImportant Topic of Physics: Electrostatic Field

Important Topic of Physics: Electrostatic Field


An electrostatic field exists between two objects that have different electrical charges and are in close proximity to each other. An electrostatic field forms around any single electrically charged object in relation to its surroundings. If an object has an excess of electrons in comparison to its surroundings, it is negatively charged (-). A positively charged (+) object is one that is deficient in electrons in comparison to its surroundings.

Electrostatic fields are similar to magnetic fields in some ways. Objects attract when their charges have opposite polarities (+/-); objects repel when their charges have the same polarity (+/+ or -/-). Lines of electrostatic flux in the vicinity of two oppositely charged objects are analogous to magnetic flux lines between and around two opposite magnetic poles. Electrostatic and magnetic fields differ in other ways.

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    Metallic objects block electrostatic fields, whereas magnetic fields can pass through most (but not all) metals. When charge carriers, such as electrons, are stationary, electrostatic fields can exist as a result of a potential difference or a voltage gradient (hence the “static” in “electrostatic”).

    Magnetic fields form as a result of the movement of charge carriers and the flow of current. A fluctuating magnetic field is produced when charge carriers are accelerated (rather than moving at constant velocity). This generates a varying electric field, which in turn generates a varying magnetic field.

    As a result, both fields can spread across vast distances in space, creating a “leapfrog” effect. An electromagnetic field is a type of synergistic field that allows wireless communications, broadcasting, and control systems to function.


    Electrostatics is a branch of physics concerned with the study of electric charges at rest (static electricity). Some materials, such as amber, have been known since classical times to attract lightweight particles after rubbing. The word ‘electricity’ was thus derived from the Greek word v (elektron), (amber).

    Electrostatic phenomena are caused by the forces that electric charges exert on one other. Coulomb’s law describes such forces. Despite the fact that electrostatically induced forces appear to be relatively weak, some electrostatic forces are relatively large.

    The force between an electron and a proton, which make up a hydrogen atom, is approximately 36 orders of magnitude greater than the gravitational force acting between them. There are numerous examples of electrostatic phenomena, ranging from the simple attraction of plastic wrap to one’s hand after removing it from a package to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturing, and the operation of photocopiers and laser printers.

    The study of the accumulation of charge on the surface of things as a result of contact with other surfaces is known as electrostatics. Although charge exchange occurs whenever two surfaces come into contact and separate, the effects of charge exchange are usually only noticed when at least one of the surfaces has a high resistance to electrical flow, because of the charges that transfer are trapped there for a long enough time to be observed.

    These charges then remain attached to the object until they either bleed off to the ground or are quickly neutralized by a discharge. The neutralization of charge built up in the body as a result of contact with insulated surfaces causes a static “shock.”

    Because of electrostatic induction, the electrostatic field (lines with arrows) of a nearby positive charge (+ causes the mobile charges in conductive objects to separate. Negative charges (blue) are attracted to the surface of the object facing the external charge and move there.

    Positive charges (red) are repelled and move to the surface, away from the surface. Because these induced surface charges are precisely the right size and shape, their opposing electric field cancels the external charge’s electric field throughout the interior of the metal.

    As a result, the electrostatic field inside a conductive object is zero everywhere, and the electrostatic potential is constant.

    Define electrostatic field:

    Electrostatic fields are stationary electric fields that do not change over time. Such fields exist when charged matter systems are stationary or when electric currents are constant. Coulomb’s law fully describes the field in that case. Electric charges, both positive and negative, generate the electric field.

    Like charges repel and opposite charges attract in the same way that like poles on magnets repel and opposite poles attract. Any molecule or atom can be neutral (with no net charge), positively or negatively charged.

    Electrostatic field formula:

    The Electric Field formula is written as


    The electric force is given by if q and Q are two charges separated by r.



    We acquire the Electric Field Formula by substituting the electric force formula into the electric field formula.

    When a voltage V is applied over a certain distance r, the electric field formula is as follows:


    Electrostatic field SI unit:

    The electric field is defined as the force per unit of positive charge.



    The electric field is measured in SI units NC-1

    Also read: Important Topic of Physics: Potential Difference

    Frequently Asked Question (FAQs):

    Question: How does a positive charge affect the radius of a flexible ring?

    Answer: Increases as a result of repulsion

    Question: A positively charged glass rod attracts a suspended straw ball. Is it safe to assume that the ball is negatively charged?

    Answer: Yes, because opposite charges attract one another. When a positively charged glass rod attracts a negatively charged straw ball, this indicates that the ball is negatively charged.

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