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Finding Electric Potential From Electric Field01:13

Finding Electric Potential From Electric Field

For a system of charges, it is easy to calculate the system's potential because potential is a scalar quantity. However, in some instances where calculating the electric field is more straightforward than finding the potential, the electric field is used to calculate the system's potential. For a positive charge, the electric field is radially outward, and the potential is positive at any finite distance from the positive charge. In such an electric field, the motion away from the positive...
Electric Potential Energy01:20

Electric Potential Energy

When an electric field accelerates a free positive charge q, it is given kinetic energy. The process is analogous to an object accelerated by a gravitational field as if the charge were going down an electrical hill where its electric potential energy is converted into kinetic energy. Of course, the sources of the forces are very different. The work done on a charge q by the electric field in this process helps to develop a definition of electric potential energy.
The electrostatic or Coulomb...
Electric Potential and Potential Difference01:16

Electric Potential and Potential Difference

Suppose a positive test charge moves away from a positive static charge, then the Coulomb force does positive work, and its electric potential energy decreases. The potential energy per unit charge is defined as the electric potential. The electric potential is independent of the test charge.
When a test charge moves from the initial to the final position, the electric potential difference between those positions is defined as the ratio of the change in the potential energy to the charge on the...
The Resting Membrane Potential01:21

The Resting Membrane Potential

Overview
Electromotive Force02:36

Electromotive Force

Electricity is generated by either electrons or ions flowing through a solution or a conducting medium. This flow of electrons or specifically electrical charge is defined as an electric current. When electrons move through a wire, they generate an electric current. It can be recalled that in a redox reaction, electrons are lost and gained. In the spontaneous redox reaction of zinc with copper, when zinc is immersed in a copper ion solution, a transfer of electrons from one substance to...
Electromotive Force01:02

Electromotive Force

Electromotive force (emf) is the force that causes current to flow from a higher to a lower  potential. The term "electromotive force" is used for historical reasons, even though emf is not a force at all.
Any circuit with a constant current must contain an emf-producing source. Examples of emf sources include batteries, electric generators, solar cells, thermocouples, and fuel cells. All these sources transform energy of some kind (mechanical, chemical, thermal, and so on) into electric...