Physics > Electrostatics > 10.0 Work done

  Electrostatics
    1.0 Introduction
    2.0 Electric charge
    3.0 Coulomb's law
    4.0 Principle of superposition
    5.0 Continuous charge distribution
    6.0 Electric field
    7.0 Electric field lines
    8.0 Insulators and conductors
    9.0 Gauss's law
    10.0 Work done
    11.0 Electric potential energy
    12.0 Electric Potential
    13.0 Electric dipole

10.3 Relation between work done by electrical & external force

The relation between work done by electrical and external force is given by, $${W_{{\text{electrical force}}}} = - {W_{{\text{external force}}}}$$

From the table below we can easily understand the relation and difference between the two types of work done.



Work done by electrical forceWork done by external force


$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = \int {\overrightarrow F } .\,d\overrightarrow r $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = \int {Fdr\cos \left( {0^\circ } \right)} $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = F\int {dr} $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = Fd$$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = qEd$$
$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = - \int {\overrightarrow F } .\,d\overrightarrow r $$$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = - \int {Fdr\cos \left( {0^\circ } \right)} $$$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = - F\int {dr} $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = - Fd$$$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = - qEd$$


$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = \int {\overrightarrow F } .\,d\overrightarrow r $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = \int {Fdr\cos \left( {180^\circ } \right)} $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = - F\int {dr} $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = - Fd$$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = - qEd$$
$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = - \int {\overrightarrow F } .\,d\overrightarrow r $$$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = - \int {Fdr\cos \left( {180^\circ } \right)} $$$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = F\int {dr} $$$${\left( {{W_{A \to B}}} \right)_{{\text{electrical force}}}} = Fd$$$${\left( {{W_{A \to B}}} \right)_{{\text{external force}}}} = qEd$$


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