Potential Difference Vs Potential Gradiant
Potential Difference
As the units of measure for Potential Difference are volts, potential difference is mainly called voltage. Individual voltages connected in series can be added together to give us a “total voltage” sum of the circuit as seen in the resistors in series. Voltages across components that are connected in parallel will always be of the same value as seen in the resistors in parallel , for example.
For series connected voltages: Vs = V1 + V2 + V3 + ..........
For parallel connected voltages: Vp = V1 = V2 = V3 = ..........
By using Ohm’s Law, the current flowing through a resistor can be calculated as follows:
Calculate the current flowing through a 100Ω resistor that has one of its terminals connected to 50 volts and the other terminal connected to 30 volts.
Voltage at terminal A is equal to 50v and the voltage at terminal B is equal to 30v. Therefore, the voltage across the resistor is given as:
VA = 50v, VB = 30v, therefore, VA – VB = 50 – 30 = 20v
The voltage across the resistor is 20v, then the current flowing through the resistor is given as:
I = VAB ÷ R = 20V ÷ 100Ω = 200mA
POTENTIAL GRADIENT
Potential gradient is defined as “rate of change of potential with respect to distance” and is generally represented as ∂V/ ∂x, where x represents distance, V is potential and all other variables of the equation are constant
In all cases, the equipotentials are at right angles to the field lines. The separation of the equipotentials tells you about the field.
Evenly spaced equipotentials - it's a uniform field.
Increasing separation - a weakening field.
In fact, the rate of change of spacing between equipotentials is called the ''potential gradient'' and it can be shown that Field strength, E = potential gradient = dV/ dX
