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The concept of potential difference is central to understanding electric fields. It refers to the difference in electric potential between two points in space. In simpler terms, it's the work needed to move a unit charge from one point to another. Electric potential is measured in volts (V), and when we talk about potential difference, we're usually discussing two specific points, such as points A and B.
The potential difference, \(\Delta V\), between two points A and B is given by the equation:

• \(\Delta V = V_B - V_A\)

In this problem, the potential at point A is 95 volts, and at point B, it's 28 volts. So, the potential difference is calculated as \(\Delta V = 28 \mathrm{~V} - 95 \mathrm{~V} = -67 \mathrm{~V}\).Understanding this negative sign is crucial. It indicates that as we move from A to B, the electric potential decreases by 67 volts.
The negative potential means point B is at a lower potential than point A, which directly affects the direction of the electric field.

Electric potential, often simply called voltage, represents the electric potential energy per unit charge at a point in space. Think of it like an "electric height" from which charges "fall," with higher voltages being like mountain peaks and lower voltages like valleys.

• A charge at a point with higher potential has more stored energy.
• The unit of electric potential is the volt (V).

In this exercise, points A and B have different potentials, with A having a higher potential (95 V) than B (28 V). This difference creates potential energy for charges moving between these points. Charges will naturally move from higher potential (A) to lower potential (B), much like how water flows downhill.
The electric potential is a scalar quantity, which means it doesn't have direction. But, potential differences between points do result in directional effects, such as forces and fields acting on charges within that field.

A uniform electric field is a field in which the electric force exerted on a charge is the same no matter where the charge is located in the field. This means the field lines are parallel and equally spaced.
Electric fields are typically represented by the symbol \(E\), with units of volts per meter (V/m). In a uniform field, the electric potential difference between two points is directly related to the field strength and the distance between them:

• \(E = -\frac{\Delta V}{d}\)

In our problem, the field is uniform between points A and B. Using the potential difference \(\Delta V = -67\) V and the distance \(d = 0.016\) meters, the magnitude of the electric field is calculated as \[E = -\frac{-67 \mathrm{~V}}{0.016 \mathrm{~m}} = 4187.5 \mathrm{~V/m}\]The uniform electric field indicates that no matter where you place a charge between A and B, it will experience the same electric force. The direction, described by the negative potential difference, is from A (higher potential) to B (lower potential), showing how charges respond naturally to electric forces.