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EXERCISES

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  8. Post-listening exercises
  9. Pre-listening exercises

1. Review questions:

1, What is the primary purpose of the oscillograph?

2. What are the essential parts of the oscillograph and TV
receivers? 3. What current is the oscillograph supplied with?
4. What does the amount of deflection depend upon? 5. What
for is a saw-tooth waveform used? 6. How is a steady image
obtained?

II. Make up an abstract of the text basing on the answers
to the above questions.

III. Translate the international words without a dictionary:
pulse, period, amplitude, 'interval, diagram, synchroni­
zing, information, moment, oscillograph

IV. Define what parts of speech these words are and trans­
late them:

investigator, receiver, primary, invisible, essential, suc­cessive, initial, unnecessary, beginning, increment, retrace, superposition, reproduce, disappear, deflection, accurately

V. Translate these synonyms and memorize them:

1. image (n), representation

2. period (я), time, cycle

3. steady (adj), fixed, stable

4. device (n), gadget, instrument

5. supply (v), furnish, provide

6. show (v), indicate, illustrate, demonstrate

7. investigate (v), research, explore

8. accurately (adv), exactly

9. hence (adv), so, then, therefore, consequently
10. appear (v), become visible


VI. Translate these words and word combinations and learn

them:

besides, the same, in order to, relatively, provided, thereby, such, how, along, any

Test 1

Find the correct answer out of the three given to each question:

1. Which of the following tubes converts an electrical sig­
nal into a visual one:

a diode tube, a triode tube, a cathode-ray tube

2. In which of the following devices a cathode-ray tube is
used:

a radio-receiver, an ac amplifier, an oscillograph"

3. Which of the following particles are to be removed from
the cathode-ray tube when it is operating:
electrons, neutrons, gas molecules

4. By means of which of the following fields the electron
deflection is produced in the above mentioned tube:

a magnetic field, an electrostatic field, the combination of magnetic and electrostatic fields

5. Which of the following parts of the cathode-ray tube is
used for producing a narrow beam of electrons:

an electron gun, plates of the deflecting system, a fluo­rescent screen

6. Which of the following parts of the cathode-ray tube the
investigated signal enters:

the electron gun, the vertical deflecting plates, horizon­tal deflecting plates

Test 2

I. Find Russian equivalents for the English verbs (see p. 148):

1. mount (а) желать

2. combine (b) считать, рассматривать

3. deflect (с) случаться, появляться

4. consider (d) помещать

5.adjust (e) производить

6. place (f) объединять(ся)

7. desire (g) сокращать

8. abbreviate (h) отклонять(ся)

9. produce (i) монтировать
10. occur (j) регулировать


II. Find Russian equivalents for the English words and
word combinations (see p. 148):

1. readily (а) иначе

2. otherwise (b) посредством

3. let us (с) среди

4. in effect (d) легко

5. among (e) после; после того как

6. such as (f) давайте

7. by means of (g) такой как; как например

8. after (h) как... так и

9. both... and (i) иногда, случайно
10. occasionally (j) в действительности

III. Find Russian equivalents for the English words and
word combinations (see p. 148):

1. besides (а) тот же, самый

2. in order to (b) при условии, если

3. the same (с) такой

4. provided (d) кроме того, помимо

5. such (e) любой

6. how (f) относительно

7. relatively (g) вдоль, по

8. any (h) посредством этого

9. along (i) как

10. thereby (j) для того, чтобы

IV. Match these synonyms (see pp. 148):

1. give off (a) in effect

2. means (n) (b) emit

3. hence (c) stable

4. speed (d) precise

5. steady (e) highly

6. period (f) velocity

7. accurate (g) rapidly

8. in fact (h) therefore

9. quickly (i) cycle
10. very (j) way

Test 3

Find a synonym (a), (b), (c) or (d) to the word or word com­bination in bold type:

1. The process takes place — (a) shows; (b) indicates; (c) means; (d) occurs


2. To accelerate electrons — (a) conduct; (b) focus;
(c) emit; (d) speed up

3. To regulate a device — (a) produce; (b) fix; (c) ad­
just; (d) construct

4. To choose a conductor — (a) apply; (b) use; (c) con­
nect; (d) select

5. A broad beam — (a) long; (b) wide; (c) light; (d)
short

6. An electron beam — (a) flow; (b) ray; (c) gun;
(d) device

7. To indicate the polarity — (a) represent; (b) show;

(c) use; (d) provide

8. To guide electrons — (a) liberate; (b) conduct; (c) give
off; (d) accelerate

9. A difficult job — (a) task; (b) work; (c) situation;

(d) position

10. The applied technique — (a) machine; (b) instrument;
(d method; (d) device

11. To consist of elementary particles — (a) knock out;

(b) depend 6n; (c) find; (d) be made up of

12. To investigate the voltage — (a) research; (b) deter­
mine; (c) know; (d) measure

13. A highly sensitive device — (a) good; (b) new;

(c) very; (d) modern

14. Several devices — (a) a lot of; (b) the same; (c) five;

(d) a few

15. The battery supplies energy — (a) uses; (b) changes;
(c) furnishes; (d) adjusts

16. To move rapidly — (a) in the same way; (b) quickly:
(c) slowly; (d) quietly

17. Accurately obtained trace — (a) usually; (b) earlier;
(c) exactly; (d) previously

18. The image of the input signal — (a) form; (b) speed;
(c) period; (d) representation

19. The essential part of — (a) main; (b) other; (c) sec­
ond; (d) last

20. The same kind of matter — (a) work; (b) substance;
(c) energy; (d) voltage

Test 4

Finish each sentence choosing one of the three variants (a),

(b) or (c) based on the texts from Section V: 1. Cathode-ray tubes provide...


(a) the generating of the sound waves; (b) amplifi­cation of low electrical signal; (c) a visual representa­tion of voltage and current waveforms.

2. Cathode-ray tubes consist of...

(a) one basic component; (b) two basic components; (g) three basic components.

3. One of the essential parts of a cathode-ray tube is...

(a) an electron gun; (b) a source of positive voltage; (c) a transistor amplifier.

4. A narrow beam produced by an electron gun accelerates
focuses and consists of...

(a) positive ions; (b) electrons; (c) protons,

5. A deflection system...

(a) produces electrons; (b) deflects the electron beam; (c) is the source of electrons.

6. A fluorescent screen produces...

(a) an electron beam; (b) an alternating current; (c) a spot of visible light. 7. The fluorescent screen is covered with...

(a) fluorescent materials; (b) conducting coating of carbon particles; (c) a thin copper coating.

8. The essential parts of a cathode-ray tube are housed in...

(a) a hollow cylinder; (b) a glass envelope; (c) a me­tal box.

9. The method used for removing the electrons from the
screen and returning them to the cathode is...

(a) to place the Aquadag coating; (b) to remove the cathode; (c) to place an anode battery.

10. The essential part of all oscillograph and TV receivers
is...

(a) a transistor oscillator; (b) a cathode-ray tube; (c) a generator of the alternating current.

11. The primary purpose of the oscillograph is to convert...

(a) electric signals into visual images; (b) an alter­nating current into a direct current; (c) a saw-tooth waveform into a sinewave.

12. The oscillograph comprises, besides the cathode-ray
tube...

(a) a sinewave voltage oscillator; (b) the scanning, deflection and synchronizing circuits; (c) a tube tank circuit.

13. The electron gun of the cathode-ray tube of the oscillo­
graph is supplied with...

(a) dc voltage; (b) ac voltage; (c) a dumping sinewave.


14. The voltage of the signal investigated enters...

(a) the horizontal deflection input of the amplifier;

(b) the vertical deflection input of the amplifier; (c) the
filament circuit of the cathode-ray tube.

15. The amount of vertical deflection depends on...

(a) the strength of the current of the cathode-ray tube;

(b) the input signal of the horizontal amplifier;

(c) the voltage of the output signal of the vertical amplifier.

16. Scanning is accomplished by...

(a) deflecting electron beams along the horizontal line;

(b) changing the filament voltage of the cathode-ray tube;

(c) changing the amount of electrons getting on the

fluorescent screen.

17. A waveform that provides the relatively slow linear
rise in amplitude and rapid retrace to zero has the ap­
pearance of...

(a) the straight line; (b) the sinewave; (c) the teeth of a saw.

18. A waveform that has the appearance of the teeth of a
saw is called...

(a) a saw-tooth waveform; (b) a dc voltage waveform;

(c) a sinewave.

19. To obtain a steady image on the oscillograph screen it
is necessary...

(a) to change sharply the filament voltage in accordance with the

input signal;

(b) to overlay most accurate­ly the previously obtained trace;

(c) to reduce the light spot on the screen of the oscillograph.

20. Superposition can be obtained only, provided...

(a) the input signal is slowly changed;

(b) the saw­tooth voltage is absent;

(c) each sweep coincides with the beginning of each

successive period of the input signal.

(See keys to the tests on p. 148)

Translate into Russian without a dictionary.

TEXT

1. Cathode-ray tubes convert an electrical signal into a visual one by shooting a beam of electrons at a fluorescent screen and deflecting the beam in accordance with the variations of the electrical signal. Cathode-ray tubes consist of an electron-gun, a deflection system, and a fluorescent screen, all housed in a glass envelope.

2. The electron gun — usually made up of a heater-type cathode, a control grid, an accelerating electrode or grid, a focusing anode, and a final accelerating anode — produces, accelerates and focuses the emitted electrons into a narrow beam. It acts as an electron emitter and electronic lens system.

3. The fluorescent screen is coated with a phosphor zinc silicate, zinc oxide, zinc sulphide that produces visible light when electrons impinge on it.

4. The oscillograph comprises the cathode-ray tube, the scanning, deflection and synchronizing circuits. It is supplied with a direct current. The oscillograph converts electric signals into visual images. To obtain a steady image on the oscillograph screen it is necessary for each trace produced in each period of scanning to overlay most accurately the previously obtained trace.


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