We measure the voltage between two points but why? what is the reason behind it? If you don’t know then don’t worry because today we are doing to discuss that Why Voltages Are Measured Between Two Points?
Voltages are always measured with respect to a reference, so you need two points, one the reference and the other the point where it is being measured.
Voltage is a difference in potential between two points, where one point is at higher potential and the other is at a lower potential, therefore the difference is what matters and is termed as potential difference or voltage. If ΔV is the potential difference between points A and B then ;
∆V = ∆U/q = W(BA)/q
∆U is the potential energy difference between points A and B, and W(BA) is the work done in moving a unit charge q between these two points.