Give the relation between electric field and electric potential .

Explanation

Consider a positive charge q kept fixed at the origin . To move a unit positive charge by a small distance dx in the electric field E, the work done is given by dW=-Edx. The minus sign implies that work is done against the electric field . This work done is equal to electric potential difference . Therefore,
dW=dV. `" " "or" " "` dV=-Edx
Hence `E=-(dV)/(dx)`
The electric field is the negative gradient of the electric potential .