SSS3 Physics: Capacitors and Capacitance

Summary A capacitor is a device used to store electrical charge and electrical energy. It consists of at least two electrical conductors separated by a distance. (Note that such electrical conductors are sometimes referred to as “electrodes,” but more correctly, they are “capacitor plates.”) The space between capacitors may simply be a vacuum, and, in that case, a capacitor is then known as a “vacuum capacitor.” However, the space is usually filled with an insulating material known as a dielectric. (You will learn more about dielectrics in the sections on dielectrics later in this chapter.) The amount of storage in a capacitor is determined by a property called capacitance, which you will learn more about a bit later in this section. Summery We have seen in this tutorial that the job of a capacitor is to store electrical charge onto its plates. The amount of electrical charge that a capacitor can store on its plates is known as its Capacitance value and depends upon three main factors. Surface Area – the surface area, A of the two conductive plates which make up the capacitor, the larger the area the greater the capacitance. Distance – the distance, d between the two plates, the smaller the distance the greater the capacitance. Dielectric Material – the type of material which separates the two plates called the “dielectric”, the higher the permittivity of the dielectric the greater the capacitance. Learning Objectives After this lesson, students should be able to: Explain capacitance and its usage Explain the concepts of a capacitor and its capacitance Describe how to evaluate the capacitance of a system of conductors. Calculate capacitance Remember to sign up to our channel, there's a new class every week! For more help with learning Physics, visit our website: http://learnathome.ng/ Enjoy!