Work Done Moving Charge: Understanding Electric Potential

The question asks us to identify the concept that defines the work done when a charge is moved from one pole to another through a wire. Let's analyze the definitions related to moving charges in an electrical circuit.

Defining Work Done in Moving a Charge

Work is done when a force causes a displacement. In the context of electricity, moving an electric charge requires work to be done against electrical forces, especially if there's a difference in electrical potential between the starting and ending points.

• Work Done: The energy required to move a charge from one point to another.
• Charge: A fundamental property of matter, measured in Coulombs (C).
• Poles: Typically refer to the terminals of a power source (like a battery), which have different electric potentials.
• Wire: A conductor providing a path for the charge to move.

The relationship between work done ($W$), charge ($q$), and the potential difference ($\Delta V$) between two points is given by the formula:

$$ W = q \Delta V $$

This formula highlights that the work done in moving a charge is directly proportional to the charge itself and the potential difference it moves through.

Analyzing the Options

Let's look at why 'Electric potential' is the correct choice and why the others are not:

1. Electric power

   Electric power is the rate at which energy is transferred or work is done. It is calculated as Power = Work / Time ($P = W/t$). While related to work done, it is not the definition of the work done itself, but rather how fast that work is performed.

2. Electric static field

   An electric field is a region where a charged particle experiences a force. While the electric field exerts forces that contribute to the work done, the field itself isn't the measure of the work done in moving a charge between two points.

3. Electric potential

   Electric potential is defined as the work done per unit charge in moving a charge from a reference point to a specific point in an electric field. The difference in electric potential (Voltage) between two points is precisely the work done per unit charge to move a charge between those points. Therefore, the work done in moving a charge from one pole to another through a wire is directly defined by the electric potential difference between the poles.

4. Electric current

   Electric current is the rate of flow of electric charge (Current = Charge / Time, $I = q/t$). It measures how much charge is moving per second, not the work done in moving that charge.

In summary, moving a charge between two points with a potential difference requires work, and 'Electric potential' (specifically, the difference in potential) is the concept that quantizes this work relative to the charge moved.