2. Read and translate the following international words:

Nouns (n): academy, anode, author, battery, cathode, detector, diode, electricity, electrode, electron, electronics, element, energy, engineer, experiment, expert, gas, hobby, institute, method, million, operation, patent, pharmacology, principle, process, profession, radio, rouble, signal, student, symbol, vacuum, voltage.

Adjectives (adj): effective, electric, medical, neg­ative, official, positive.

Verbs (v): register, process.

3. Consult the table above and write full sentences. Use is/are. Where possible change sentences to use isn’t/aren’t.

1. Rectifier …. an electrical device.

2. There … an anode and a cathode in a diode.

3. … it easy to explain the operation of semiconductor devices?

4. New devices … more powerful.

5. In some diodes there … a gas and current flows from one element to the other through a gas.

6. Look at fig. X. This … a cathode and these … a plate and a battery.

7. The physical principles of this phenomenon may … quite different.

8. Anodes … positively charged electrodes by which the electrons leave a device.

9. Electronics … a science which studies the conduction of electricity in a vacuum, gases and semiconductors.

10. Cathodes (in electron tubes) … electrodes from which emission takes place.

11. Diode … a device that permits current to flow through it in only one direction.

12. There … a lot of analogue and digital equipment at our university.

4. Complete the sentences using the following verbs: emit(s), occur(s), flow(s), define(s), repel(s), attract(s), have(has).

1. We can … electronics as the study of conduction of electricity in a vacuum, in gases and in semiconductors.

2. The conduction of electricity in a vacuum for example … in vacuum tubes.

3. Though in some vacuum tubes current … from one element to the other through a gas.

4. Every vacuum tube diode … a cathode with a heater and a plate.

5. When the circuit is completed the cathode … electrons.

6. Negative voltage on the cathode … electrons.

7. Positive voltage on the plate … electrons.

5. Put the verb into the correct form. Insert always/never/often/sometimes/usually.

1. The current (flow) through the tube.

2. If a nega­tive voltage is applied to the plate current (not flow).

3. Thus a diode (permit) current (flow) in only one direction.

4. A semiconductor diode also (conduct) current in one di­rection, but the physical principles, which (permit) it to do this (be) different.

5. We (use) diodes as rectifiers of alternating voltages, as detectors of radio signals, as switching devices, etc.

6. An English dictionary of electronics (define) this sci­ence as "the study of con­duction of electricity in a vacuum, in gases and in semiconductors".

7. Do you (know) that in some diodes there is a gas, and current (flow) from one ele­ment to the other through a gas?

8. And can you (give) an exam­ple of conduction of elec­tricity in a vacuum? This (occur) in vacuum tubes.