Question

How is potential gradient measured?

Answer 1

To understand what potential gradient is and how it is measured, first we need to know what actual gradient is. In physics, gradient is the rate of change with respect to distance of a variable quantity, as temperature or pressure.

Complete answer:
The potential gradient is defined as the potential difference (the fall of potential from the high potential end) per unit length of the wire. In other words, it represents the slope along which potential is changing.
The potential gradient is the potential difference per unit length. The SI unit of the potential gradient can be determined by substituting the unit of potential difference or voltage and length. Therefore, the unit of potential difference is $\dfrac{{Volt}}{{Meter}}$.
As we know that in the definition of potential gradient, we have two important factors which are, potential difference and the length. So, to measure the potential gradient of a wire, first we need to measure the potential difference between its end and then with the help of a measuring instrument, we have to precisely measure the length of the wire. Once we have done this, we will divide the potential difference by the length of the wire and we will get the desired value of the potential gradient.

Note:
One of the important uses and applications of potential gradients is that while making cables, the value of dielectric insulation provided is kept higher than the potential gradient of the conductor, else the cable is not safe.