Say you have to power a simple motor with a solar panel, but that panel does not always supply the necessary power. What is the simplest circuit that could combine a DC motor, Solar panel and battery backup to ensure that the motor will continue running even when the solar panel cannot supply power?
How does the texture of a surface affect the concentration of charge on that surface?
Say we compare a balloon (smooth) and a football (textured) (ignoring material differences) and give them the same total charge. Then we introduce dust particles. How do the two surfaces attract dust...