Exercise 1: Match the English words with their Russian equivalents

ELECTRIC CIRCUIT

Electric circuitis an unbroken path along which an electric current is able to flow. A simple circuit might consist of an electric cell (the power source), two conducting wires (one end of each being attached to each terminal of the cell), and a small lamp (the load) to which the free ends of the wires leading from the cell are attached. When the connections are made properly, current flows, the circuit is said to be “ closed,” and the lamp will light. The current flows from the cell along one wire to the lamp, through the lamp, and along the other wire back to the cell. When the wires are disconnected, the circuit is said to be “ open ” or “broken.” In practice, circuits are opened by such devices as switches and circuit breakers.

Two general circuit classifications are series and parallel. The elements of a series circuit are connected end to end; the same current flows through its parts one after another. The elements of a parallel circuit are connected so that each component has the same voltage across its terminals; the current flow is divided among its parts.

When two circuit elements are connected in series, their effective resistance is equal to the sum of the separate resistances; the current is the same in each component throughout the circuit. When circuit elements are connected in parallel, the total resistance is less than that of the element having the least resistance, and the total current is equal to the sum of the currents in the individual branches.

A battery-powered circuit is an example of a direct-current circuit; the voltages and currents are constant in magnitude and do not vary with time. In alternating-current circuits, the voltage and current periodically reverse direction with time. Lighting circuits and electrical machinery use alternating current circuits. Many other devices, including computers, stereo systems, and television sets, must first convert the alternating current to direct current. That is done by a special internal circuit usually called a power supply.

Magnetic circuits are analogous to electric circuits, where magnetic materials are regarded as conductors of magnetic flux. Magnetic circuits can be part of an electric circuit; a transformer is an example. Equivalent circuits are used in circuit analysis as a modeling tool; a simple circuit made up of a resistor, and an inductor might be used to electrically represent a loudspeaker. Electrical circuits can also be used in other fields of studies. In the study of heat flow, for example, a resistor is used to represent thermal insulation.

Active vocabulary:

Electric circuit, an unbroken path, to flow, an electric cell, conducting wire, load, switch, circuit breaker, voltage, terminal, effective resistance, direct current, alternating current, reverse, lighting circuits, internal circuit, a power supply, magnetic circuit, magnetic flux, an inductor, heat flow, thermal insulation.

Exercise 1: Match the English words with their Russian equivalents

1) thermal insulation	a) изменять (направление)
2) heat flow	b) магнитный поток
3) magnetic flux	c) теплоизоляция
4) electric cell	d) переключатель
5) reverse	e) осветительная цепь
6) lighting circuit	f) тепловой поток
7) switch	g) гальванический элемент

Дата добавления: 2015-10-29