III. Find English equivalents.

 

Звено, дефект, неисправный, оборудование, установка, служить, вплоть до, использовать, плавить, защищать.

IV. Finish the sentences.

 

1. Fuses are widely used………….

2. Fuses serve to………………….

3. Quartz-sand fuses serve………..

4. Fuses are commonly used………

5. Fuse protection is based on……..

6. Fuses are used both in…………..

V. Insert the missing letter.

Equi-ment, insta-lation, uti-ize, qu-rtz, exc-ed, prin-iple, ind-strial, fu-ible.

VI. Make up the sentences.

1. devices used nowadays. Fuses are widely as protection

2. fuses in different nowadays types are of use There

3. is simple principle based Fuse very on a: protection

4. are used Fuses direct both in and current alternating current circuits.

5. This opens the circuit and the circuit disconnects the power from source.

 

VII. Complete the sentences using the correct variant:

 

1. A fuse serves                               a) as a load.

                                                         b) as a protection.

2. Fuses are used                            a) for d.c. only.

                                                         b) for both a.c. and d.c.

3. In case of a fault                         a) the whole fuse should be replaced.

                                                          b) the faulty link should be replaced.

4. Fuse protection is based on        a) a simple principle.

                                                          b) a complex principle.

VIII. Memorize the questions. Use them in a talk with your group mate:

 

1.What does a fuse serve for?

2.For what type of current are fuses used?

3.What should be done in case of a faulty fuse?

4.What principle is fuse protection based on?

                                       ПРАКТИЧЕСКАЯ РАБОТА № 17

                             

COMPONENTS OF ELECTRIC CIRCUITS

 

Цели: Введение и активизация в речи лексики по теме «Компоненты электрических цепей».

Оборудование: комплект тестов, раздаточный материал.

 

                                   Vocabulary

I. Learn the words and expressions.

Incandescence                                накал, накаливание

Incandescent lamp                                 лампа накаливания

Copper  Steel To convert To deliver According to Etc. = et cetera II. Read and translate the text.

медь сталь преобразовывать питать, подавать согласно и так далее

The main components of any circuit are devices that produce and utilize electric energy. They are: 1. power sources, 2. utilizing loads, 3. connecting conductors.

The most common power sources are electric generators and primary cells. Electric generators convert chemical energy into electric energy.

Loads include electric heaters, electric motors, incandescent lamps, etc. Motors convert electric energy into mechanical, incandescent lamps and heaters convert electric energy into light and heat. Utilizing devices or loads convert electric energy into thermal, mechanical or chemical energy.

Electric power is delivered from power sources to loads by electric wires. According to their material, wires can be aluminum, copper, steel, etc.

 

III. Find English equivalents.

накал, лампа накаливания, накаливание, медь, сталь, питать, подавать преобразовывать,

 

   IV. Add necessary letter.

Comp-nent, cond-ctor, gen-rator, he-ter, mec-anical, alum-num, uti-ize, ope-ation.

V. Finish the sentences.

1. The main components of any circuit are……

2. The most common power sources are………

3. Loads include………

4. Motors convert……….

5. Electric power is…......

 

VI. Make a dialogue.  

Say a few words about your electrical engineering laboratory. Say what power sources and what loads are utilized there. Have a talk with your group mate about their types and their operation.

VII. Answer these questions:

 

1.What are the main components of an electric circuit?

2.What is the function of an electric source?

3.What is the function of a load?

4.What is the function of wire conductors?

5. What other devices are utilized in a circuit

 

 

ПРАКТИЧЕСКАЯ РАБОТА № 18

PRACTICAL UNITS

Цель: Введение и активизация лексики по теме «Единицы измерения электричества».

Оборудование: комплект тестов, раздаточный материал, иллюстрации по теме.

 

Vocabulary

I. Learn the words and expressions.

 

Electrical (power)

The main unit

A current

A pressure

A voltage

A resistance

Flow

To form

To be measured

Electromotive force

To cause

To join

A cell

A circuit

A substance

To offer

The ohm

To represent

To connect

In succession

In series

In parallel

D.c. (direct current)

A.c. (alternating current)

An equation

To transform

To found

A product

A terminal

A value

энергетика

главный раздел

ток

давление

напряжение

сопротивление

поток, течь

образовывать

измеряться

электродвижущая сила

вызывать

соединять

элемент

цепь

вещество, материя

предлагать, оказывать

Ом

представлять

соединять

последовательно

последовательное соединение

параллельное соединение

постоянный ток

переменный ток

уравнение

превращать, преобразовывать

основывать

продукт, произведение

зажим, ввод, вывод

величина, ценность

II. Read the text and say what an electrical current is. Give the full answer.

Practical Units

The main units in electrical engineering are those relating to current, pressure or voltage, resistance, power, and energy.

Current is that which flows along the conductors forming the electric circuit. It is measured in amperes. Pressure, potential, voltage or electromotive force is that which causes a current to flow between two points when they are jointed by a conductor. The unit is the volt.

The total pressure generated by a cell or generator is called its electromotive force (e.m.f). The difference in pressure between any points in a circuit is simply know as the potential difference, voltage, or pressure of the circuit. The opposition which a substance offers to the flow of current through it is called its resistance. Substance having a small resistance, such as metals and most liquids, are called conductors, those offering a high resistance are called insulators. The unit of resistance is the ohm, represented by the Greek letter. A megohm equals one million ohms.

When resistance's are connected in succession to form a circuit, they are said to be connected in series. The total resistance of such a circuit is the sum of all the resistance. Resistance's connected to the same terminals are said to be in parallel.

In a circuit in which a steady direct current is flowing there is a direct relation between the current, voltage and resistance, temperature remaining constant, and this is expressed by what is known as Ohm's law.

The law is represented by the following e quation

I - current in amperes

 R - resistance in ohms

 E - voltage in volts

The power in a d.c. circuit is found from the product of the amperes flowing in it and pressure at its terminals. The unit of power is the watt. It is the power in a circuit when a current of one ampere flows under a pressure of one volt. The practical unit of electrical energy is the kilowatt-hour (k.w.h.). It is the energy transformed in a circuit when the power is one kilowatt and the time taken is one hour. In general practice this value is spoken of as a unit, and is the basis of charges for electrical energy.