4. Электрометр

Условие задания: Подвесьте лёгкий шарик на нити между двумя заряженными пластинами. Если шарик зарядить, он отклонится в сторону на некоторый угол. С какой точностью это устройство позволяет измерять величину заряда шарика? Оптимизируйте устройство для измерения как можно меньшего заряда. Описание видео: This is a demonstration of capacitor charge, carried out by suspending a ball between two capacitor plates of opposite charges. When the ball touches one plate, it acquires charge of the same sign as that plate. The ball is then attracted to the other plate, acquires charge of the same sign as that plate, and returns to the first plate, and so on, the result being fast oscillations of the ball between the two plates. This demonstration was created at Utah State University by Professor Boyd F. Edwards, assisted by James Coburn (demonstration specialist), David Evans (videography), and Rebecca Whitney (closed captions), with support from Jan Sojka, Physics Department Head,