# How do I Get the Value for an Electric Potential Difference Between 2 Points?

**How do I Get the Value for an Electric Potential Difference Between 2 Points?**

The difference in electric potential between two points, also known as voltage, electric potential difference, electric pressure, or electric tension, is defined as the effort required per unit of charge to move a test charge between the two places. Volt is the derived unit for potential difference (voltage)in the International System of Units. Work per unit charge is measured in joules per coulomb in SI units, with 1 volt equaling 1 joule per 1 coulomb. Power and current were employed in the previous SI definition for volt; starting in 1990, the quantum Hall and Josephson effects were utilized, and most recently (2019), basic physical constants were added for the definition of all derived units and SI units.

The physical effects of electrical charge or imbalances, also via a magnetic field and time-variable magnetic fields (e.g., dynamo or generator), or a combination of them, can produce electrical potential differences between points. In addition, electrochemical processes (cells and batteries) and the piezoelectric action of pressure and heat produced by emf through metal-metal junctions can cause the potential difference to a macroscopic scale. These final microscopic processes have the above physical basis.

A voltmeter can be utilized to measure the voltage (or potential difference) between two points in an arrangement; often, one of the sites is a common reference potential such as the system’s ground. A voltage can indicate either a source of energy (electromotive force) or energy that has been lost, utilized, or stored.

Water flowing in a closed circuit of pipes, powered by a mechanical pump, is a simple analogue for an electric circuit. This is known as a “water circuit.” The pressure differential between two points is equal to the difference in potential between two points. Water flowing from one place to the other can accomplish work, such as spinning a turbine, if the pump causes a pressure differential between them. Similarly, an electric current generated by a potential difference produced by a battery can do work. The voltage produced by a fully charged vehicle battery, for example, may “push” a high current through the starting motor’s windings.The pump will not revolve if the pump is not operating since there is no pressure difference. Similarly, if the car’s battery is very weak or “dead” (or “flat”), the starting motor will not spin.

Many electrical concepts may be explained using the hydraulic analogy. The “pressure drop” multiplied by the amount of water transported equals the effort done to move water in such a system. Similarly, the effort required to transfer electrons or other charge carriers in an electrical circuit is equal to the “electrical pressure differential” multiplied by the number of electrical charges carried. The higher the “pressure differential” between two locations, the greater the flow between them in terms of “flow.”

The term “voltage” is frequently used to describe the voltage dropped across an electrical equipment (such as a resistor). The difference between measurements at each terminal of the device with respect to a common reference point is the voltage drop across the device (or ground). The difference between the two measurements is the voltage drop.A voltage of zero exists between two locations in an electric circuit that are linked by an ideal conductor with no resistance and are not in a changing magnetic field. A conductor can link any two locations with the same potential, but no current will flow between them.A voltage of zero exists between two points in an electric circuit that are linked by an ideal conductor with no resistance and are not in a changing magnetic field. A conductor can link any two locations with the same potential, but no current will flow between them.

The voltmeter, the potentiometer and the oscilloscope are important for measuring voltages. Analog voltmeters, such as spindles, measure the current by a fixed resistor that is proportional to the voltage across all the resistance according to Ohm’s law. The potentiometer is used to balance the unknown voltage v with a known voltage in a bridge circuit. The cathode ray oscilloscope is used to magnify the voltage and to remove the electron beam from a straight path so that the beam is proportionate to the voltage.

In a letter to Giovanni Aldini in 1798 Volta initially applied the phrase electromotive force, and first appeared in a publication of the Annales de chemie et de physique in 1801. Thus Volta meant a force, which was especially an electrochemical force, not an electrostatic force. The phrase “electromagnetic induction” has been used in the 1820s by Michael Faraday.

Now, coming to the question, we get

Let’s see the force on one Q.

F= kQ^{2}/4a^{2}+ kqQ/a^{2}

For the system to be equilibrium F=0.

kQ^{2}/4a^{2}+ kqQ/a^{2}=0

q=−4Q.

We hope the above information is helpful to you.

Learn more from the concepts from the chapter Current Electricity from Class 12 Physics