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UNIT 10Task 1. Study new words and word combinations.
TASK 2. Read the text and translate it from English into Russian. CAPACITANCE AND CAPACITORS If two conductors are separated by an insulating space and a charge is given to the plates, the opposite sort on each side, then a potential difference exists between the plates. The two plates, together with the insulating space, have capacitance. Devices which have the ability to condense the charge are called condensers or capacitors. The simplest condenser consists of two plates separated by an insulator. Its capacitance depends on its shape, size and material. Every condenser does not consist merely of two plates, there may be very many, but they are connected together in such a way that one group is separated from the other by the dielectric. In practice the most common types of dielectrics are: air, mica, paper, plastics, etc. Two common types of condensers are in use nowadays: a fixed condenser and a variable one. There are three quantities which can be varied: the plate area, the distance between the plates and the dielectric. The basic unit of capacitance is the farad. The farad (F) is too large a unit for practical purposes and the practical units in use are the microfarad (mF) and the micromicrofarad (mmF), sometimes called the picofarad (pF). TASK 3. Answer the following questions and retell the text. 1. What devices are called condensers? 2. What does the simplest condenser consist of? 3. What does the capacitance of a condenser depend on? 4. In what way are the plates of a condenser connected together if a capacitor consists more than of two plates? 5. What are the most common types of dielectrics? 6. What types of condensers are in use nowadays? 7. What quantities can be varied in a condenser? 8. What is the basic unit of capacitance? TASK 4. Translate the following words, pay attention to the prefix: reproduce, repay, recreate, remark, reform, retell, rebuild, reconstruct, readjust. TASK 5. Match the words. 1. device а) ослаблять 2. size b) слюда 3. charge c) поток 4. potential difference d) заряд 5. exist e) электродвижущая сила ЭДС 6. mica f) существовать 7. electromotive force g) устройство, прибор 8. flux h) разность потенциалов 9. weaken i) величина, размер TASK 6. Fill in the gaps and translate the sentences. 1. The unit of measurement of . . . is the Ohm. a) capacitance; b) resistance; c) conductor. 2. The . . . of capacitance is called the farad. a) device; b) po1е; c) unit. 3. The main parts of a . . . are metal plates and insulators. a) resistor; b) amplifier; c) capacitor. 4. The . . . of a variable capacitor move. a) insulators; b) plates; c) units. 5. Both electromotive force and . . . are measured in volts. a) resistance; b) potential difference;с) capacitance. 6. The plates of a . . . cannot be moved. a) variable capacitor; b) fixed capacitor; c) insulator. 7. Capacitance is the . . . of a circuit that opposes any change of voltage in a circuit. a) property; b) application; c) source. 8. A fixed capacitor has . . . produced of paper, mica and other materials. a) insulators; b) plates; c) oscillators. TASK 7. Transform the sentences from Present Simple Passive into Past (Future) Simple Passive. 1. Fixed capacitors are used in telephone and radio devices. 2. Automatic devices are made in our laboratory. 3. The plates of a condenser are separated by an insulator. 4. Scientific reports are published in our magazine. 5. The two parts of a magnet that show the strongest magnetism are called the North Pole and the South Pole. TASK 8. Fill in the gaps using Present, Past or Future Simple Passive Voice. 1. This phenomenon … (to study) by a group of scientists two months ago. 2. A device which has the ability to condense a charge of electricity … (to call) a capacitor. 3. A new transmitting station … (to build) in this region next year. 4. Copper … (to use) to produce wire conductors. 5. Yesterday a very interesting experiment … (to make) in our laboratory. 6. The properties of silver … (to discuss) next week. TASK 9. Fill in the gaps using Present, Past, Future Simple Active or Passive Voice. 1. Every student knows that an insulator … (to call) a dielectric. 2. The engineer … (to find) practical application of these circuits, the results were good. 3. The simplest condenser … (to consist) of two plates separated by an insulator. 4. These three quantities … (to measure) in our experiment next week. 5. Radio … (to invent) in Russia. 6. When the current is small, a galvanometer … (to use). 7. They … (to measure) these quantities tomorrow. 8. This young engineer … (to make) a new device and we used it in our experiment. TASK 10. Ask questions to the words in bald. 1. Devices which have the ability to condense the charge are called condensers. 2. An ohmmeter is used to measure the value of resistance in a circuit. 3. The proton was discovered by Rutherford. 4. Many technical problems will be solved by Russian scientists in the near future. 5. Electromagnetic waves are used in radio and television transmission. 6. A rheostat is used to change resistance of circuits, and in this way to vary the value of current. 7. The theory of radio-transmitting and radio receiving devices was improved by Russian scientists. 8. Amplifiers are used when we want to make signals bigger. TASK 11. Listen to the recording and fill in the gaps with numbers and units. SIMBA ELECTRONICS AVC 1) … . Ceramic disc capacitor. 2) … per unit. Non-polarized multilayer ceramic capacitor. Flame-retardant. Typically used for coupling, and bypass applications. Capacitance: 3) … Voltage rating: 4) … Operating temperature range: 5) … AVP 6) … . Plastic (mylar) capacitor. 6) … per unit. Non-polarized polyester film (mylar) insulator and metal plates encased within a hard epoxy coating. Coating protects against moisture. Designed for use in general purpose DC applications. Capacity: 7) … Voltage rating: 8) … Operating temperature range: 9) … AVE 10) … . Electrolytic capacitor. 11) … per unit. Aluminum capacitors designed for applications needing high capacitance, low cost, and very small size such as in personal computers and medical electronics. Capacitance: 12) … Voltage rating: 13) … Operating temperature range: 14) … All of our capacitors contain marks indicating, at minimum, their capacitance. Check out our tantalum capacitors and trimmer capacitors on the next page! |