Potential Difference vs Voltage
Potential difference and voltage are two terms used in engineering to describe a difference of the potential in two points. Voltage is referred to electricity where potential difference can be related to electrical, magnetic and gravitational fields. However, if only the electric field is concerned, potential difference is same as the voltage.
Potential is a concept used in electric, magnetic and gravitational fields. Potential is a function of the location and potential difference between point A and point B is calculated by subtracting the potential of A from potential of B. In other words, gravitational potential difference between points A and B, is the amount of work that should be done to move a unit mass (1 kg) from point B to point A. In an electric field, it is the amount of work to be done to move a unit charge (+1 Coulomb) from B to A. Gravitational potential difference is measured in J/kg where electric potential difference is measured in V (Volts).
However, in common use, the term ‘potential difference’ is mostly used to describe electrical potential differences. Therefore, we have to use this term carefully to avoid misinterpretations.
Electrical potential difference between point A and B is also known as the voltage between point A and point B. Voltage is measured in the unit Volts (V). Voltmeter is the equipment used to measure voltage. A battery provides a voltage between its two ends (electrodes) and its positive side has a higher potential and negative electrode has a lower potential.
In a circuit, current flows from the higher potential to lower potential. When it goes through a resister, a voltage between two ends can be observed. This is called as a ‘voltage drop’. Although the voltage is always between two points, sometimes people ask for a voltage of a point. This is about the voltage between that particular point and a reference point. This reference point is usually ‘grounded’ and electrical potential of it is considered as 0V.
What is the difference between Potential Difference and Voltage?
1. Potential difference can be found in any field (gravitational, electrical, magnetic etc), and voltage is only used for electric fields.
2. Potential difference with respect to electric field is called as the voltage.
3. Voltage is measured in Volts (V) and unit of measuring potential difference is changed with the type of the energy field (V for electric, J/kg for gravitational etc).