How to Demonstrate the Voltage on a charged object in Physics Laboratory

TL;DR

This paper presents a simple method to measure the voltage on charged objects using basic instruments, enabling calculation of their charge and demonstrating electrostatic principles in a physics lab setting.

Contribution

It introduces an accessible technique to measure voltage and charge on charged objects with simple capacitors and CMOS voltmeters, enhancing educational demonstrations.

Findings

Charged objects exhibit measurable potential differences.

The method allows calculation of average charge on objects.

A simple capacitance meter for electrostatics is proposed.

Abstract

Common Objects like a comb or a pen get charged when rubbed against something like human hair or garment clothing. Charged objects exhibit noticeable attractive or repulsive force lifting small pieces of paper or pushing/pulling a suspended light object charged with the same/opposite(uncharged) polarity respectively. This indicates the strong electrical nature of charged objects. Flashes due to spark between oppositely charged objects can be seen in total darkness. Implying a large potential difference between these charged objects which is not possible at lower voltages. This article describes a method to measure the voltage on commonly charged objects with respect to earth using simple instrumentation based on capacitors and CMOS voltmeter. Once the potential difference is known the average charge on the object can be calculated as well. The article also suggests a simple femto-farad capacitance meter for electrostatics work.