# Physics Week 22: Capacitance and Electrical Energy Storage

Lesson one of week 22 focused of electrical potential with a dipole, capacitance, and energy storage. Diagrams and equations were drawn out to show how all the concepts work and then a couple of practice problems followed. Dipoles occur frequently in physics and chemistry, so it was nice to see how this concept related to both fields.

Lesson two was about learning what capacitors do and how they work. A capacitor (or a battery for a more familiar example) is used to store electric charge and is sometimes called a condenser. In a capacitor there are two flat plates, usually coiled up to save space, with one positively charged and the other negatively charged. During the end of the lesson equations were explained on how to determine capacitance. A bunch more examples followed.

Lesson three continued to build on what was taught in lesson two. We practiced determining capacitance again and learned about dielectrics and dielectric constants. A dielectric is an insulating sheet that is in between the two plates in the capacitor. Because the dielectrics break down more easily than air, the plates can be closer together, increasing the capacitance or electric storage.

Lesson four continued the topic of dielectrics and capacitors. Capacitors store charge, which can be thought of as potential energy. The potential energy is equal to the work it took to charge the capacitor, and charge * voltage = work. Therefore, when you first start to charge the capacitor, there is no voltage, and while it is charging the average voltage is ½ the final voltage.

A bunch more examples and practice problems followed.

Even though this week covered very few topics, I sort of felt like everything was jumbled up. In the end I learned everything and figured it out, but all of the concepts were spread throughout all the lessons, making it difficult to understand everything.