Question

Explain how, using a capacitor in conjunction with a gold-leaf electroscope, the voltage sensitivity 

of the electroscope may be increased.

Answer 1

We can increase the sensitivity by connecting the golden-leaf electroscope to a charged capacitor. Assume that the leaves of the electroscope diverge at voltage greater or equal to V. So, the leaves will not diverge at voltages lower than V. By connecting c charged capacitor, we add its voltage to the measured voltage, so, we may observe divergence of the leaves at voltages that are smaller than V because some additional voltage is supplied by the capacitor.