Capacitance

Capacitance measures the amount of stored charge per voltage. When capacitance is high, the quantity of stored charge is also high while little electric potential is used. Its units are referred to as farads. To change the capacitance of plates, the amount of conductive material between them, which is called dielectric, has to decrease. This photograph contains a computer's keyboard, which is a common example of capacitance. When someone presses a key, the distance between the plates of the key changes, a message is sent to the computer, and the symbol appears on the screen. In order for this symbol to stop appearing, the key's capacitance has to return to its initial value.

Battery LIfe

Although the terms are similar, electric potential and electric potential energy are not the same. While energy is measured in joules, volts are the units of electric potential. Also, electric potential is the amount of potential energy, or work, for each charge. Like other changes in energy, electric potential energy is based on force and displacement. This photograph contains different types of batteries. Although batteries may have different sizes, the amount of potential energy per charge can the same for all of them. However, the size of the battery determines how long it lives. Smaller batteries do not last as long as larger ones with the same voltage because a larger battery can keep more potential energy.

Electric Forces

Similar to how matter and momentum are conserved, the net charge of an isolated system will also remain constant. This picture shows two spheres with a cord between them. This is meant to serve as a model of a system involving metal spheres. If the sphere on the left has a charge of +4 C and the one on the right has one of -2 C, the electric force would be 8 N attractive since they are unlike charges. The total charge of the system is 2 C, the sum of 4 and -2. If a wire connected them, each of their charges would become the same. Since the total charge is 2 C, each would have 1 C for its charge. As a result, the force of the spheres would be 1 N repulsive since the charges are the alike.

Introducing Electricity

An electric charge causes a force between objects. Unlike momentum or acceleration, people cannot see electrically charged atoms with their own eyes, let alone the particles that compose them. The charge of an object is either positive or negative. This picture contains a fork and a cup. The fork is made out of metal, which is a conductor. Conductors are materials that transfer electrons easily because they want to give them up. This is characteristic of a positive charge. Meanwhile, the cup is created with glass, which is an insulator. Insulators do not transfer electrons easily because they want to take electrons, which is a quality of a negative charge.