Задания на проверку усвоения лексико-грамматического материала основного текста и на закрепление навыков самостоятельной работы с английским языком
31. / 6 мин./ а) Используя заметки, сделанные при выполнении задания 30, постарайтесь воспроизвести диалог, б) Продолжите беседу, расширяя, углубляя и изменяя тему диалог.
32. / 3 мин./ Парная работа. Объяните своему собеседнику какие данные необходимо указать при заказе новых щеток.
33. / 8 мин./ Некоторые из следующих отрицательных предложений построены грамматическшнеправильно. Ука$к ите их и аргументируйте свой выбор. Переведите на русский язык грамматически правильные предложения.
1. Nothing has not ever been done. 2. The method does not employ any temporary filling. 3. No details are available. 4. Never could not this reaction be expected. 5. It is not improbable. 6. It not infrequently happens. 7. It did not take them more than 2 hours to carry out this operation.-8. It did take them more than 2 hours to carry out this operation. 9. The machine must not be placed on no solid & even foundation to prevent vibration.
34. / 5 мин./ Ответьте на вопросы по-английски.
1. What may be some of the sources of trouble in insulation & cooling? 2. How do you go about keeping the pipes of the heat exchanger clean? 3. What may be the reason for the cooling capacity reduction? 4. What precautions must be observed in preventing corrosion? 5. Is too high flow rate harmful or harmless?
35. / 3 мин./ Заполните пропуски в предложениях, мысленно обращаясь к содержанию основного текста.
1. When the water flow ... too much, it is indicated by the water flow ... & by temperature rise ... . 2. The instructions for ... of the air-to-water heat... are usually delivered with the machine. 3. Special care must be taken not to ... coil with the cleaning tools.
36. /4 мин./ Составьте три предложения из следующих наборов слов.
1. machine, unuse, long, time, keep, dry. 2. remove, bearing, cover, inspection, lubrication. 3. flow, cooling, keep, close, value, instruct.
37. / 3 мин./ Закончите предложения.
1. The condition of the water flow alarm.device can be checked by means of.... 2. The uncleanness on the winding surfaces causes ... . 3. If, however, it is suspected that rrioisture has got into the machine, measure....
38. /6 мин./ Напишите по-английски рекомендации по предотвращению попадания влаги в электрическую машину.
39. / 6 мин./ Подробно опишите и объясните свои действия по поддержанию электрической машины в хорошем рабочем состоянии. /В скобках указаны номера абзацев основного текста./
1. Keep the machine clean! /4/ 2. Clean open-type machines inside! /9, 10, 11/ 3. Keep stand-by machines in a dry place! /12,13/
40. / 20 мин./ Читая текст, выпишите ключевые слова из каждого предложения и напишите 5 вопросов, ответы на которые дали бы краткое описание усилителя.
Automatic Means of Control & Inspection.
Magnetic Amplifiers /МА/.
MA are commonly used for automatic control of machines & installations of hundred kilowatts of power, & also as preamplifiers for precision measurement device whose output power is measured by fractional watts. MA are capable of amplifying a dc signal of 10 >IS watt of power. The simpliest MA design includes a ferromagnetic core /or a soft magnetic material/ with two windings, one in an ac, the other in a dc circuit. Gain is achieved due to the dc biasing of the core, which increases considerably the current in the ac winding, since the magnetic induction-intensity /flux density-to-field strength/ relationship is nonlinear. The limitation is an emf generated in the dc winding by the ac winding. The emf in the dc winding is much less in another form of MA which has two identical cores each having two windings. Sections of the control /dc/ windings are connected in series & oppose each other to cancel part of tne emf induced in each of the two windings.
MA are cheap, reliable in operation &, having .no moving elements, simple in maitenance. Various MA designs are available for a wide range of temperature, humidity & pressure conditions. They are generally fire-& explosion-proof-because of absence of sparking & high-heat elements. Of high efficiency, MA are found valuable for contactless /static/ automatic control systems where high reliability is a factor. Other design versions include reversible MA suitable for controlling two-phase asynchronous electric motors & similar drives. Also MA can be used singularly & as series components in cascaded /multi-stage/ amplifiers.
