Перепишите следующие предложения; укажите видо- временную форму глаголов-сказуемых. Подчеркните причастие 1 и причастие 2, входящие в состав глаголов- сказуемых.

Перепишите следующие предложения; укажите видо- временную форму глаголов-сказуемых. Подчеркните причастие 1 и причастие 2, входящие в состав глаголов- сказуемых.

Electronics is becoming increasingly important in branches of production

2. The engineers have designed modern motor-cycles with air-cooled engines.

3. Scientists of many countries have been working hard to find out the secretof theatom.

Перепишите следующие предложения; подчеркните в каждом из них пассивную конструкцию. Переведите предложения на русский язык.

1. Electric current is generated at power plants and is transmitted to different parts of the country.

2. The transformer was invented and the first electric lines were set up at the end of the 19 th century.

3. New devices are being used in many branches of science and technology.

4. Since the invention induction motors have been improved and their power has increased.

 

Перепишите следующие предложения; переведите их, обращая внимание на инфинитивные конструкции.

1.When we switch on an electric drill, we expect it to run rapidly up to the concrete speed.

2. Everyone who tries an experiment will be disappointed to discover how weak the electric force is.

 

Прочтите и переведите 1й и 2й абзацы текста. Перепишите и письменно переведите 2й, 3й и 4й абзацы текста.

ELECTRIC MOTORS

1. Electric motors are to much a part of everyday life that we hardly realize it. When we switch on an electric drill, for example, we expect it to run rapidly up to the correct speed and we won't question how it is that enough energy is drawn from the supply to bring it up to speed, and when we finish work the power reduces automatically without intervention on our part.

2.If one understands the electrical principles of how the motors

works, he will be ablе to appreciate its potential and its limitations

see him it`s already remarkable performance can be even further improved by the addition of external controls.

3.Nearly all motors exploit the force that can be exerted on a current-carrying conductor, which has been placed in a magnetic field. The force can be demonstrated by placing a bar magnet near a wire carrying current, but anyone who tries the experiment will probably he disappointed to discover how weak the force is, and will doubdess be wondering how to such an effect can be used to make effective motors.

4. In order to make the most of the mechanism we need to arrange a very strong magnetic field and interaction with many conductors. Although the magnetic field (or excitation) in essential for the work of a motor it acts only as a catalyst, and all of the mechanical output power comes from the electrical supply to the conductors on which the force is developed.

5. In some motors the parts of the machines responsible for the excitation and for converting of energy are separated and easily distinguished. In DC motor, for example, the excitation is рrovided either by permanent magnets or by field coils that are wrapped around poles on the stationary part while the conductors on which force is developed are on the rotor and they are supplied with current via brushes. In many motors, however, there is no physical distinction between the "excitation" and "energy-converting" parts of the machine and a single stator winding serves both purposes.

 

 

6. Прочтите 5й абзац текста и вопрос к нему. Из приведенных вариантов ответа укажите номер предложения, содержащего правильный ответ на поставленный вопрос.

 

What motors have " excitation " and "energy-converting" parts?

1)All motors

2)DC motors

3) Some motors

Вариант 2

1. Перепишите следующие предложения; подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму. Переведите предложения на русский язык.

1. When the electrons move in one direction an electric current results.

2. The practical use of electricity became possible after developing electromagnetic machines.

3. The scientists concluded that some electrons were moving through the vacuum.

4. Physicists have not only studied of atomic nucleus fission, but they have opened the way to the fusion of atomic nuclei.

Прочтите и устно переведите 1й абзац текста. Перепишите и письменно переведите 2й, 3й и 4й абзацы текста.

DC Motors

 

1.When current is passed through the armatureof a DC motor, a torque is generated by magnetic reaction, and the armature revolves. The revolution of the armature induces a voltage in the armature windings. This voltage is opposite in direction to the outside voltage applied to the armature, and hence is called back voltage or counter electromotive force (emf).

2. As the motor rotates more rapidly, the back voltage rises until it is almost equal to the applied voltage. The current is then small, and the speed of the motor will remain constant as long as the motor is not under load and is performing no mechanical work except that required to turn the armature.

3. Under load the armature turns more slowly, so it reduces the back voltage and permits a larger current to flow in the armature. The motor is thus able to receive more electric power from the supply and to do more mechanical work.

4. Because the speed of rotation controls the flow of current in the armature, special devices must be used for starting DC motors. When the armature is at rest, it has virtually no resistance, and if die normal working voltage is applied, a large current will flow, which may damage the commutator or the armature windings. The usual means of preventing such damage is the use of a starting resistance in series with the armature to lower the current until the motor begins to develop an adequate back voltage. As the motor picks up speed, the resistance is gradually reduced, either manually or automatically.

5. The speed at which a DC motor operates depends on the strength of the magnetic field acting on the armature, as well as on the armature current. The stronger the field, the slower is the rate of rotation needed to generate a back voltage large enough to counteract the applied voltage. For this reason the speed of DC motors can be controlled by varying the field current.

6) Прочитайте 5 абзац текста и выберите правильное утверждение;

The speed of a DC motor depends on

a) tile strength of the magnetic field acting on the armature

b) the armature current

с) both die armature field and current

 

КОНТРОЛЬНАЯ РАБОТА №2

Для того чтобы правильно выполнить контрольную работу необходимо усвоить следующие разделы курса английского языка:

1. Простые неличные формы глагола: Participle 1, Participle 2 в функциях определения и обстоятельства.

2. Герундий (Gerund) и его функции в предложении.

3. Атрибутивные группы и их перевод.

 

ВАРИАНТ 1

Перепишите следующие предложения; подчеркните в каждом из них Participle 1, Participle 2 и установите функции каждого из них в предложении, т.е. укажите, является ли оно определением, обстоятельством или частью глагола сказуемого. Переведите предложения на русский язык.

 

1. Raising the temperature we increase agitation of molecules.

2. Nearly all properties of matter are effected in some degree by temperature changes.

3. The insertion of an ammeter into a circuit must not change the magnitude of the current flowing.

4. The worked performed showed good results.

5. The substances that must have a long time to be heated will keep their heat much longer that those can be heated more rapidly.

 

Перепишите следующие предложения; укажите видо- временную форму глаголов-сказуемых. Подчеркните причастие 1 и причастие 2, входящие в состав глаголов- сказуемых.

Electronics is becoming increasingly important in branches of production

2. The engineers have designed modern motor-cycles with air-cooled engines.

3. Scientists of many countries have been working hard to find out the secretof theatom.