The energy associated with the positive charge increases when it moves in a direction opposite to that of the electric field.

Why this happens (quick explanation)

  • The electric field direction is defined as the direction a positive test charge naturally wants to move.
  • If the positive charge instead moves opposite to the electric field, it is effectively being pushed “uphill” in electric potential.
  • Moving “uphill” in potential means its electric potential energy increases , just like lifting a mass higher in a gravitational field increases its gravitational potential energy.
  • This increase in potential energy usually comes from external work being done on the charge (for example, by an external force or a power source), so its kinetic energy may decrease if no extra energy is supplied.

So, in simple terms:

A positive charge moving opposite to the electric field gains electric potential energy.