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UNIT 8Task 1. Study new words and word combinations.
TASK 2. Read the following sentences, pay attention to the suffixes used. Inductor induces inductance. A productive producer produces post-production products. An inventive inventor invents new inventions every day. Physics studies physical phenomena. A reflecting reflector reflects reflected signals. TASK 3.Study the following table of Participle I and Participle II.
TASK 4. Form ParticipleI and ParticipleII using the following verbs: invent, transform, generate, induce, transmit, plan, wind, oppose, change, characterize, resist, consist, contain. TASK 5. Translate from English into Russian: computer-assisted, plastic–coated, program-controlled, air-cooled, battery-driven, signal-generated, program-installed, man-made, hardware-maintained, error-protected. TASK 6. Read the text. Translate it, pay attention to the words in bald. Make up 10 questions. INDUCTORS An inductor, also called a coil or reactor, is a passive two-terminal electrical component which resists changes in electric current passing through it. It consists of a conductor such as a wire, usually wound into a coil. Energy is stored in a magnetic field in the coil as long as current flows. When the current flowing through an inductor changes, the time-varying magnetic field induces a voltage in the conductor, according to Faraday’s law of electromagnetic induction. According to Lenz's law the direction of induced EMF is always such that it opposes the change in current that created it. As a result, inductors always oppose a change in current. An inductor is characterized by its inductance, the ratio of the voltage to the rate of change of current, which has units of Henries (H). Many inductors have a magnetic core made of iron or ferrite inside the coil, which serves to increase the magnetic field and thus the inductance. Along with capacitors and resistors, inductors are one of the three passive linear circuit elements that make up electric circuits. Inductors are widely used in alternating current (AC) electronic equipment, particularly in radio equipment. They are used to block AC while allowing DC to pass; inductors designed for this purpose are called chokes. They are also used in electronic filters to separate signals of different frequencies, and in combination with capacitors to make tuned circuits, used to tune radio and TV receivers. TASK 7. Make up three sentences which would be true, false, or not given according to the information given in the text. Model: There are only two passive linear elements in a circuit. (This sentence is false as there are three of them: capacitor, inductor and resistor) Inductance is measured in Henries. (This sentence is true) The coil is usually made of copper. (This information is not give; nothing is said about the material used to produce coils) TASK 8. Listen to the recording and decide whether these statements are true or false: Electricity which moves from batteries is called direct current. Direct current flows from the positive electrode to the negative one. Alternating current changes its polarity while it flows from positive to negative. Hertz is the unit of measurement used to describe the speed of polarity change. A transformer can be used to measure the current in the circuit. Rectification is the process switching AC into DC with the help of diodes or transformers. The ability to store electricity in an electric field is called capacitor. The ability to store electricity in a magnetic field is called inductance. Reactance is the way capacitors and inductors influence AC. Inductance is a way to assess how easy it is for electricity to pass through an electrical device. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||