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Chapter 22

Electric Charges and Fields

From lightning during thunderstorms to electronic devices, the phenomenon of electromagnetism is all around us. The electromagnetic force is one of the …
All objects we see around us consist of atoms, which combine to form molecules. The lightest element in the universe is hydrogen, and a hydrogen atom …
Some materials may easily let electrical charges pass through them, while others obstruct their flow. The former are called conductors and the latter …
The Earth is a good conductor of electricity, and it is so big that it can be considered an infinite source or sink of charges. It can easily exchange …
Experiments with electric charges have shown that if two objects each have an electric charge, they exert an electric force on each other. The magnitude …
Coulomb's Law describes the force experienced by two point charges under each other's presence. But what if there are more than two charges? For …
Consider two point charges, each exerting Coulomb force on the other. It is possible to describe the Coulomb interaction via an intermediate step by …
Atoms generally contain the same number of positively and negatively charged particles, protons, and electrons. Hence, they are electrically neutral. …
Imagine a bucket of water. It contains many molecules, of the order of 1026 molecules. Thus, although it contains discrete elements (molecules) at the …
In physics, symmetry in a system means that something in the considered system remains unchanged due to a specific operation to which it is subjected. For …
The three-dimensional representation of the electric field of a positive point charge requires tracing the electric field vectors, whose lengths decrease …
The definition of electric field lines greatly eases the visualization of electric fields, a vector field, especially in the presence of many charges. The …
Consider two charges of equal magnitude but opposite signs. If they cannot be separated by an external electric field, the system is called a permanent …
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the …
There are four fundamental forces in nature: the gravitational force, the electromagnetic force, the strong nuclear force, and the weak nuclear force. To …
The simplest case of a surface charge distribution is the uniformly charged disk. Calculating its electric field also helps us calculate the electric …
This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water …
A method of carrier number control by electrolyte gating is demonstrated. We have obtained WS2 thin flakes with atomically flat surface via scotch tape …
Clinical studies show electrical stimulation (ES) to be a potential therapy for the healing and regeneration of various tissues. Understanding the …