since we have the formaula E= - integral of v.dr. Explain the formaula, why - sign is used?

Dear student,

 

Because the electric field is the negative gradient of electric potential, the electric field lines are everywhere normal to the equipotential surface and points in the direction of decreasing potential.Electric potential is a scalar quantity, hence dV (as a function of x, y and z variables) can be written as:

 

 

 Hence the Electric field intensity (E) is the negative gradient of Electric potential (V).

- The negative sign shows that E is directed from higher to lower values of V i.e. E is opposite to the direction in which V increases.

Hope this helps.

Team

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