The electric current is directed movement of charged particles. It occurs when there is potential difference, i.e. in the presence of electric voltage. Electrical energy is produced in large quantities in various plants, but being many miles from civilization, there is hardly a wire, so long as to reach to the nearest outlet. And electricity in small quantities, can be extracted in nature.

The discomfort causes too dry air, but the same feeling and will cause too high humidity air. To control and maintain the required limits of relative humidity of air should be able to define it. There are several types of special devices (glucometers), with which it is possible to measure the relative humidity of air: hairline, membrane, psychometric, weight (absolute).

Historically, in the case of radio waves often indicate the frequency, and in relation to the light radiation wavelength. However, since both types of radiation have the same physical nature, if necessary, a translation of one of these quantities in another.

The scale shows how many times the card reduces the real area that it depicts. Only by knowing this value, you can defer on the map or plan of the area real distance. To know the scale can be marked on the map. If not there, calculate it according to the lines of latitude.

Called neodymium permanent rare earth magnets, known for their high resistance to demagnetization. They are used in heavy and food industry, medicine, computers and many other areas.

Generator Tesla is a device created by a brilliant Serbian scientist Nikola Tesla in the nineteenth century. In industry the principle of operation of this generator is used in microwave ovens. In ordinary life, here already more than hundred years generator Tesla serves as an exciting entertainment to the public. Electrical discharges that are generated by this device can reach a length of several meters. Now we'll show you how to create a generator Tesla at home.

To precipitation include rain, hail, snow, which represent fallen from the clouds water in different aggregate States. The measurement of the amount of precipitation is of great scientific interest, is of great practical importance, for example, to calculate the gutters, and reduced to measuring the amount of water collected in a vessel of a certain volume per unit time (day). Using this method it is possible to know the thickness of the layer of water that would have formed on earth, if water is not leaking into the ground and does not evaporate. Thanks to the installation of recorders on the rain gauges can determine the duration and intensity of the precipitation. To determine the age of the device in mind long-standing interest to the measurement of rainfall is impossible. In the Great encyclopedia edited by S. N. Yuzhakova, published in the early 20th century, and its contemporary encyclopedic dictionary F. A. Brockhaus and Efron, E. A., describes in detail the structure of the rain gauges (precipitation gauges) and their analogues equipped with recorders, pluviographs, and the methods of measuring precipitation, which has not fundamentally changed in our days. Currently, the precipitation measurement is performed by automatic pluviographs, and high precision measurement carried out by the radar mounted on radar stations in the Central aerological Observatory of the Federal service for Hydrometeorology and environmental monitoring.

Temperature is called the average kinetic energy of particles in the system, which is in thermodynamic equilibrium. This implies that temperature should be measured in energy units included in the SI system in Joules. But, historically, that the temperature was being measured long before the advent of molecular-kinetic theory and in practice using standard units – degrees. In international SI unit of measurement of the thermodynamic temperature of the body is the Kelvin (K), which is one of the seven base units in the system. In practice, however, most temperature is measured in degrees Celsius.

Legume – a family name of plants of the dicotyledonous class. All members have a legume flowers are irregular in shape and their fruits have a specific device that botanists refer to as Bob. The legume family is spread all over the world and everywhere they have representatives of their class.

Despite all the advantages of AC proved N. Tesla, his ideas were for the time forgotten. The Americans, followers of his famous countryman, completely abandoned the transmission and consumption DC only at the end of 2007

To measure the inductance of the coil, use an ammeter, voltmeter and frequency counter (if not known, the frequency of the AC source, then take readings and calculate the inductance. In the case of the solenoid (coil whose length is much greater its diameter) to determine the inductance required to measure the length of the solenoid, the area of its cross section and number of turns of the conductor.

To correctly calculate the capacitor parameters in the process of development and production, it is necessary to know the dielectric constant.

After replacement of the scale or other repair need to check accuracy or to calibrate the scale of the voltmeter. This check can be done in several simple ways. Depending on the required accuracy and the available devices, use one of the methods described below.

Since the internal energy of a gas is the sum of all kinetic energies of its molecules, then measuring it directly is not possible. Therefore, for its calculation, use the special formulas, which Express the value of using such macroscopic parameters as temperature, volume and pressure.

Chemical reactions do not affect the nuclei of atoms. Chemical properties of elements depend on the structure of their electron shells. The state of electrons in an atom is described four quantum numbers, Pauli principle, rule Gund and the principle of least energy.

To breed and to contain the fish aquarium, it is required that the hardness of the water in the aquarium was a constant. If aquarium soil consists of coarse sand and river pebbles, the water in the aquarium will always have a certain stiffness. In aquariums which contain fish and shellfish, stiffness decreases with time because of consumption of calcium shellfish to build shells. Therefore, it is necessary to periodically increase.

Mass of goods can be gross and net. Gross in a literal translation from Italian means "rough, unclean". On the contrary the net is literally translated as "pure." Therefore, the term "net weight" means net weight of goods without packaging.

If the human body to enter a large amount of hypertonic solution, due to the significant difference in the values of osmotic pressure on opposite sides of the cell membranes of cells will dehydrate. In the case of introducing a large amount of hypotonic solution the opposite will happen: the cells begin to swell and can rupture. Therefore, injected into the body isotonic solution, an osmotic pressure equal to osmotic pressure of blood, lymph and intercellular juice. How to prepare an isotonic solution?

The powerconsumption of those or other electrical device, is measured by wattmeter. But it is not every DIY enthusiast. In its absence it is possible to measure other parameters of the circuit, which includes the consumer, and then based on these data to calculate the power consumption.

Is called oscillatory motion, which is exactly or approximately repeated in certain intervals. In real life fluctuations are quite common. For example, the beating of the human heart is the oscillatory process. It is therefore necessary to understand the essence of the phenomenon.

In the process of studying physics and some other scientific disciplines, students are faced with a term such as "reactance". Is a value denoting a specific relationship between voltage and current.

The dew point is called the maximum temperature at which in the conditions of a given humidity is the saturation of water vapor in the air. Since the dew point depends on humidity, its definition is the basis of the principle of psychrometric hygrometer.

Electrolyte – a substance that in the solid state is an insulator, i.e. does not conduct electric current, however, in dissolved or molten form becomes a conductor. Why is such an abrupt change in properties? The fact that the molecules of an electrolyte in solutions or melts dissociate into positively charged and negatively charged ions, whereby these substances in such aggregate as is capable of conducting an electric current. Electrolytic properties of most salts, acids, bases.

Under density battery know the density of the electrolyte in its banks. To measure it, take a hydrometer and measure it directly to the battery banks. If necessary, dilute sulfuric acid or a concentrate, sold in car shops, then repeat the measurement. Also, the electrolyte density can be measured with a voltmeter, depending on its EMF.

To determine the power resistor , take a voltmeter and connect in parallel to the resistor in the circuit. Then turn on the ammeter in the circuit. Take readings of current and voltage and multiply their values, the result is a power current to the resistor. It is possible to measure the power of the resistorand knowing the resistance and one of the values of the current or voltage or by using a special device – power meter.

Pascal – standard system the unit of pressure. However, in practice, often use other non – si, multiples and sub-multiples of units. This – millimeters of mercury and meters of water column, and atmosphere, bar and kilopascal, megapascal, and millipascal micropascal. To convert these units from one system to another there are special formulas.

In the human body inhaled oxygen undergoes a series of transformations. From the lungs through the blood it is carried to the organs and is involved there in vital chemical reactions. Then the red blood cells transporterowych it through the veins back to the Airways in the form of carbonic acid. The smallest vesicles of the lungs - the alveoli - are collected, this chemical compound in your capillaries, where carbon dioxide gas takes its classic look. In this form the person it exhales.

Concentration - dimensional quantity, by expressing the solution composition (in particular, the content of dissolved substances). Sometimes it happens that the value is unknown. For example, in lab top bottles may be one, just signed - HCl (hydrochloric acid). To conduct many experiments information requires much more than just a name. Therefore it is necessary to use experimental techniques such as titration or density determination.

Helium is an inert monatomic gas without color, taste and smell. One of the most common elements in the Universe, second only to hydrogen. Helium is extracted from natural gas by low temperature separation process — the so-called fractional distillation.

Benzene is an aromatic hydrocarbon, which is based on a group of carbon atoms interconnected in a loop. And that this special group is called a benzene ring or aromatic nucleus.