The greatest laws of physics Ohm's Law

George Symon Ohm (1784-1854) is a famous German physicist. In 1805 he entered the Erlangen University. Though he did not graduate from this University, he managed to write and defend a thesis in 1811. Later, he was a teacher at the gymnasiums of Gottstadt and Warburg. Beginning from 1833 he became professor at the Polytechnic School in Nürnberg, and since 1849 - at the Manchen University.

He is most famous for establishment erf the general law of the electric circuit, stating the relation between resistance, ele&omotive force, and-strength of the current jg the electric circuit. Ohm g^atect ffis relationship as follows: current is directly proportional to voltage and inversely proportional to resistance. 5*

The law was discovered experimentally and first formulated in 1826. Further,investigations made use of this law. The unit of resistance was named after Ohm at “Hie International Congress of Electricians in 1881.

Faraday's Law

Michel Faraday was a great British physicist, the founder of the theory of electron field, a member of the London Royal Society. He was bom in London in the family of a Smith. Spending a few years in the primary school, he continued his studies all by himself, reading books and listening public lectures. Greatly impressed by lectures of a well-known English chemist H.Davy, he sent him a letter asking for a job at the Royal Institute.* In 1813 Davy gave him a job of a laboratory assistant. Thanks to the brilliant talent of an experimenter, Faraday soon made himself known. All his future scientific work was carried out in the Royal Institute laboratories.

Faraday's law is formulated as follows: (a) the induced E.M.F. in a conductor is proportional to the rate at which the conductor cuts the magnetic lines of force, (b) The induced E.M.F. in a circuit is proportional to the rate of change of the number of lines of force threading the circuit.

Lenz's Law

Emil Lenz was bom a prominent Russian physicist, an Academician.

At the age of 16 he entered the Derpt University. In 1823, when being a student, he joined a 3 year round-the-world trip on board of the ship "Enterprise" as a physicist. The chief of the expedition was Kotzebu, a famous Russian seaman and explorer. In 1828 Lenz was elected adjunct-professor of the St. Petersburg Academy of Sciences for his outstanding investigations in geophysics.

hi the 30ies of the 19th century, Lenz reorganized a physical laboratory of the Academy of Sciences where he began his famous studies on electricity and magnetism. He discovered the law of the electric current emitting heat in conductors. This Іащlaid the foundation for the discovery " of the Law of conservation and conversion of energy.

The direction of the incEuceB current is such that its effect opposes the change producing it. The right-hand rule enables one to predict the direction of the induced current, and may be shown to conform with Lenz's law.

J* The induction coil, the dynamo, the transformer and the telephone are practical application of electromagnetic induction.

Coulomb’s law

Charles Coulomb (1736-1806), a member of the Paris Academy of Sciences, an outstanding Frenph physicist in the period from 1785 to 1789 stated the law of electrostatic япгі magnetic, interaction.His work in this field laid foundation for the future theoretic investigations in the electrostatics and magnet statics.

Coulomb's law is one of the principal laws of electrostatics. Ц established a relationship between the force of interaction of two static electric charges, their quantities, and the distance between them. According to Coulomb's law the absolute value of the force of repulsion of two lik^harges or the force of attraction between two unlike charges e 1 and e 2, which size, is much less than the distance between them, is inversely proportional to the square of the distance between them. He also stated the laws of rotation, dry friction, laws of interaction between magnetic poles.N All these laws were named in honor of Ch, Coulomb.

I. Find in the text English equivalents to the following words and word combinations:

1) Опір, 2) сила струму, 3) прямо пропорційно, 4) обернено пропорційно, 5) подальші дослідження, 6) випромінювати тепло,

7) перетворення енергії, 8) практичне застосування, 9) магнітна взаємодія, 10) електричний заряд, 11) величина, 12) магнітний полюс.

Date: 2015-02-16; view: 1333