The discharge of current between people dressed in woolen clothes is surprising and amusing. To understand why this happens, you should familiarize yourself with what is the electrification of bodies? Answers to emerging questions can be found in the physics section of Electrodynamics. It describes the principle of accumulation of charges by solids and the current laws of particle motion.
Basic moments
To determine what the electrification of bodies is, we consider the definitions and laws of motion of charged particles. There are two opposite types: electrons (negative) and protons (positive) charges. With their huge accumulation, an electromagnetic field is formed. And the closer the bodies with statics are located to each other, the more powerful the effect is.
After the contact of the bodies, an exchange of charges takes place, potentials equalize (attraction or repulsion disappears). Particles of the same sign tend to move away, differently attracted on the contrary. This can explain what the electrification of bodies is: the mutual influence of electromagnetic fields created by electrons and protons.
Let’s try to explain in simple terms what the electrification of bodies is: in order to form an electromagnetic field, we must first carry out an action that helps to accumulate a charge:
- friction;
- influence by a magnet;
- hit on the subject;
- chemical reaction;
- attach a power source (at least a battery) to the object through the conductors.
There are many simple experiments proving in practice the laws of electrodynamics.
Some evidence of patterns
As examples, you can conduct simple experiments for children:
- We take the usual comb flat, preferably plastic, but iron is also suitable. We use hair or other natural things: a fur coat, wig, woolen shawl or sweater. It is necessary several times to intensively rub the cloves. Before this, the paper is finely chopped and then an electrified object is brought to it. Pieces instantly stick to the comb.
- Experiments for children can be carried out with an amber stone, rubbed in a similar way. After he can attract dry blades of grass and other objects. If you bring it to a thin stream of water, we will see how it deviates towards the stone.
Woolen and silk fabrics
A glass stick is rubbed on a silk scarf. After that, almost any small object can stick to it. This is clearly noticeable when the tip is brought to the hair or thin ribbons of paper.
Ebonite items are well-electrified by rubbing against woolen fabric. And glass sticks are rubbed with silk. However, these items have a different charge. This is proved by the experience below.
The ebonite rubbed with wool will repel silk. To see this, we will hang both objects on one thread and we will gradually bring them together so that they hang freely. As a result, we will see how the fabric begins to deviate to the side.
A similar phenomenon will occur during the experiment with a glass stick and wool. Electrification of bodies during friction actually occurs due to the conversion of one energy to another.
In everyday life
Around us is constantly electrifying bodies. With friction of some objects, it becomes so high that even dimensional heavy parts are attracted to them. At home, you can observe the electrification process as follows:
- We put on cloth slippers, but not with rubber soles. We rub for a long time on the carpet or wooden floor. And if you touch the tip of your fingers with a partner, you get a discharge. In the dark it will be seen how it sparkles.
- Often ungrounded refrigerators and washing machines were also beaten by static electricity. This was due to friction of the rotating parts.
- Palms are electrified after rubbing them on the same wool or silk. Clothes on a person attract various kinds of fluffs, villi due to electrification. Girls clean it with anti-static spray so that the skirt does not stick to her legs while walking.
TVs for the same reason attract dust to screens and enclosures. And a balloon rubbed on the hair of the head can be suspended for a long time from the ceiling. The charged surface is attracted to the wallpaper or other coating.
Designations in electrodynamics
The letter q is used to classify and quantify the phenomenon of charged particles. Positive protons indicate so - + q. Negative electrons received the -q character.
For calculations, the total number of charges is used. They are folded or taken away to obtain the true level of electrification of the item. In a calm state, any level of particles is constant and has the form of the law of conservation of electric charge: q1 + q2 + ... + qN = const.
And to calculate energy, the concept of "quantum" is used. In simple terms, this is the minimum number of particles of opposite charge that can be transferred to another object per unit time. This level can be measured with a special device - an electrometer. His work is based on the accumulation of charge by a metal arrow mounted on a fixed axis. As the particle level increases , the pointer deviates, the arrow moves along the dial.
Features of the calculations:
- The forces of gravity act on the charges. But they try not to take them into account in the simplest calculations. After all, the particle sizes are very small compared to the distances covered.
- To determine the direction of motion of any selected particle, it is necessary to take into account all the forces acting from the surrounding elements. All calculations are carried out graphically: a vector diagram is compiled.
How to determine the energy?
An electroscope is a device by which the electrification of bodies is recorded. Electric charge is accumulated by a metal rod in the form of petals mounted on a dielectric base - a plastic sleeve. The whole structure is placed in a steel case so that the movable part is located in front and covered with transparent glass.
To determine the charge level, you need to bring an electrified object to the upper metal part of the device. The more particles pass, the more the petals diverge. The design drawback is the inability to record positive or negative values, all values are displayed without sign.
Experiment Tools
To confirm the forces of electrodynamics, simple physical experiments are carried out using improvised means. Some of these will be:
- Two metal discs.
- Flap of wool fabric to fit.
- Electroscope. Or your own invention: an example is a metal rod connected by a conductor to one of the disks. The latter is set horizontally by the plane. The core is located vertically, finely cut pieces of paper can be applied at the base at a short distance.
One of the disks must be taken in hand. Be sure to use dielectric gloves. The second is laid fabric.
Procedure
The essence of the experiment:
- The upper disk is tightly applied through the fabric to the lower.
- It is rotated several times and sharply put up.
- If everything is done correctly, the charge is evenly redistributed between the disk and the rod.
- Pieces of paper stick to the core.
In order for the paper to fall, you can remove the charge by simply touching the metal part of the disc with your hand without a glove.
We examined the most common and simplest ways to electrify bodies.