Current flows in a circuit due to potential difference from "summary" of Fundamentals of Physics, Volume 1 (Chapters 1 - 20) by David Halliday,Robert Resnick,Jearl Walker
When a potential difference is established in a circuit, it creates an electric field that exerts a force on the charges within the conductor. This force causes the charges to move, resulting in the flow of electric current. The potential difference, also known as voltage, is the driving force behind the movement of charges in a circuit. It is analogous to the pressure difference that causes water to flow in a pipe.
In a simple circuit consisting of a battery connected to a resistor, the potential difference provided by the battery sets up an electric field within the circuit. This electric field exerts a force on the electrons in the wire, causing them to drift in the direction of the field. The rate at which charges flow past a given point in the circuit is defined as the electric current. The greater the potential difference, the greater the force on the charges, and hence, the greater the current in the circuit.
The relationship between potential difference, current, and resistance is described by Ohm's Law, which states that the current flowing through a conductor is directly proportional to the potential difference applied across it and inversely proportional to the resistance of the conductor. Mathematically, Ohm's Law can be expressed as I = V/R, where I is the current, V is the potential difference, and R is the resistance.
In summary, current flows in a circuit due to the presence of a potential difference, which creates an electric field that drives the movement of charges. The larger the potential difference, the greater the force on the charges, leading to a higher current in the circuit. This fundamental relationship between potential difference and current is governed by Ohm's Law, which provides a quantitative description of the behavior of electric circuits.
