PAPER ELECTROSCOPE - DIY kit for Students

Static electricity is a stationary electric charge that is built up on a material. A common example of static electricity is the slight electrical shock that we can get when we touch a doorknob during dry weather. The static electricity is formed when we accumulate extra electrons (negatively-charged particles which we rub off carpeting) and they are discharged onto the doorknob. Everything is made up of atoms, and atoms are made of tiny particles, some of which are electrically charged. Most atoms are electrically neutral; the positive charges (protons in the nucleus or center of the atom) cancel out the negative charges (electrons that surround the nucleus in clouds). Opposite charges attract one another. Similar charges repel one another.

Sometimes the outer layer (the negatively - charged electrons) of atoms are rubbed off, producing atoms that have a slight positive charge. The object that did the rubbing will accumulate a slight negative charge as it gets extra electrons. During dry weather, these excess charges do not dissipate very easily, and you get static electricity. (During humid weather, the electrons flow through the damp air and the object become electrically neutral.) A Paper electroscope is an instrument used by scientists to measure the relative strength of an electric charge. A simplified version of an electroscope can be made easily and can be used to study and explore static electric charges. Early experimenters used this device to detect presence of electricity and static charges. The Paper electroscope is one of the oldest electrical instruments. William Gilbert built one in the year 1600. Nevertheless, it is still a useful device. It is easy to build, and many interesting experiments can be performed with it.

IMPORTANT PARTS OF PAPER ELECTROSCOPE Copper Coil: In copper wire, copper atoms supply the flowing electrons. Comb: Rubbing a comb on the copper coil (on a dry day), This removes some of the electrons from the comb, giving each paper a slight positive electrical charge. Like charges repulse one another, so each paper repulses the other paper. Piece of Paper & Woolen cloth: Wool is a conductive material, which means it readily gives away its electrons. STEPS: 1.This is an instrument for detecting and measuring static electricity or voltage. A Copper coil is connected to a wire and a thin piece of paper is fixed. The whole of this part of the electroscope is insulated from the body of the instrument. A Bulb (glass) front prevents air draughts but allows you to watch the behavior of the paper.

2. Now rub the comb with a woolen cloth and then rub it on the copper coil. Now observe what happens…..

OBSERVATION: When comb is rubbed on the copper coil, it spreads down two piece of papers. This means that both the papers will have the same charge. Similar charges repel each other and so the paper spreads away from the other paper - the bigger the charge the more the paper spreads. The paper of the electroscope moved away from each other because they both acquired a negative charge and repelled each other. The negatively charged comb coming near the coil repelled some of the electrons in the coil. Those electrons travel down to the paper, giving each of them extra electrons and thus a negative charge. Like charges repel, so the leaves moved away from each other.

HOW STATIC ELECTRICITY WORKS?

When two materials are rubbed together (like a balloon and your hair), one will lose electrons and one will accumulate them. Physicists have ranked materials by the order in which they lose or gain electrons. This ranking is called the turbo electric series. A small list of some common materials is shown below. When two of these substances are rubbed together, the one that is higher on the list will usually lose electrons (and accumulate a positive charge). The ones on the bottom of the list gain electrons (accumulate a negative charge).

YOU CAN TRY THIS: Rub a balloon on your hair. This removes some of the electrons from your hair and gives the balloon a slight negative charge. Now put the balloon against a wall. It will stick (if the weather is dry) since the negative charges in the balloon will re-orient the atoms of the wall, and a weak electrical force will hold the balloon in place on the wall.

Try this (for a really bad hair day): Rub a wool (not acrylic) cap on your hair (on a dry day). This removes some of the electrons from your hair, giving each hair a slight positive electrical charge. Like charges repulse one another, so each hair repulses the other hairs. The result is a mad-scientist hair-do.

FOR YOUR INFORMATION:Everything in the world consists of tiny particles called “atoms.” Atoms contain even tinier particles called “protons,” “neutrons” and “electrons.” Most atoms are neutral, which means the protons (positive-charge particles), so they cancel each other out.

Sometimes, however, the outer layer of an atom gets rubbed off. This creates atoms with a slightly positive charge. The item that rubs off the outer layer of the atom “steals” some of the extra electrons, giving it a slightly negative charge. We call this built-up

electric charge “static electricity.”

When you come in from playing in the snow and remove your hat, the hat rubs your hair and electrons move from your hair to the hat, creating a static charge. When objects have the same charge, they repel each other, which mean they try to get as far from each other as possible.

This is why static electricity makes your hair stand up. Each hair has a negative charge and repels against the other hairs.

When people think of static electricity, they often think of the shock it can cause. If you have ever scooted your sock-covered feet across the carpet, you have probably experienced the zap of static electricity. As you walk over carpet in socks, your feet rub electrons off the carpet, leaving you with a slightly negative static charge. When you reach for a doorknob, you get a shock as electrons jump from you to the knob, which conducts electricity.

You’ve probably noticed that static electricity is more noticeable during the winter months. This is because the air is very dry. In the summer, the humidity and moisture in the air help electrons move more quickly, which makes it harder to build up a big static charge?