- •2. Find the Ukrainian equivalents for the following English and word combinations:
- •3. Analyze the following words and translate them, paying attention to the negative prefixes:
- •4. Read the text and translate it: Video camera
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Put the questions to the following sentences:
- •7. Match the first part (1-8) of the sentence with the second part (a-f):
- •8. Read the supplementary text, translate and entitle it:
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-8) of the sentence with the second part (a-h):
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Put the questions to the following sentences:
- •7. Match the first part (1-8) of the sentence with the second part (a-h):
- •8. Read the supplementary text, translate and entitle it:
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Say if the following statements are true or false:
- •4. Put the questions to the following sentences:
- •5. Complete the following sentences:
- •6. Match the first part (1-8) of the sentence with the second part (a-h):
- •7. Read the supplementary text, translate and entitle it:
- •8. Work in pairs. State the advantages and disadvantages of dtv and analog tv.
- •9. Render the text: tv goes digital.
- •Fill in the blanks confusing words and memorize them:
- •2. Find the Ukrainian equivalents for the following English and word combinations:
- •3. Match two parts of word combinations:
- •4. Read the text and translate it: Computer crime
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-9) of the sentence with the second part (a-I):
- •7. Render the text: Computer crime
- •8. Work in pairs. How do you defend your computer?
- •9. Read the supplementary text, translate and entitle it:
- •1. Fill in the blanks confusing words and memorize them:
- •2. Find the Ukrainian equivalents for the following English words and word
- •3. Translate the following words and word combinations into English:
- •4. Read the text and translate it: An antenna
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-7) of the sentence with the second part (a-g):
- •7. Read the supplementary text, translate and entitle it:
- •8. Render the text: An antenna
- •9. Work in pairs. Compare the two kinds of antennas.
- •2. Find the Ukrainian equivalents for the following English words and word
- •3. Which of these words from the list are similar in your language? Do they mean the same?
- •4. Read the text and translate it: a Laser
- •Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences, using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-5) of the sentence with the second part (a-e) :
- •7. Read the supplementary text, translate and entitle it:
- •8. Render the text: Laser
- •1. Choose the right word: Say, tell, speak, talk
- •2. Find the Ukrainian equivalents for the following English and word combinations:
- •3. Match two parts of word combinations:
- •4. Read the text and translate it: Electronic Devices for the home.
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-7) of the sentence with the second part (a-g):
- •7. Read the text, translate and entitle it.
- •1. Put the words in order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-7) of the sentence with the second part (a-g):
- •7. Read the supplementary text, translate and entitle it.
- •8. Render the text: How Burglar Alarms Work
- •1. Fill in the blanks confusing words and memorize them:
- •2. Find the Ukrainian equivalents for the following English words and word combinations:
- •3. Translate the following words and word combinations into English:
- •4. Read the text and translate it: ir Remote Control Theory.
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-7) of the sentence with the second part (a-g) :
- •7. Read the supplementary text, translate and entitle it.
- •8. Render the text: ir Remote Control Theory.
- •1. Find the mistake(s) in each sentence and correct the confusing word:
- •2. Find the Ukrainian equivalents for the following English words and word
- •4. Which of these words from the list are similar in your language? Do they mean the same?
- •5. Read the text and translate it: Radar
- •1. Put the words in the right order to make a sentence:
- •2. Fill in the blanks with the following words:
- •3. Complete the following sentences using active vocabulary:
- •4. Say if the following statements are true or false:
- •5. Answer the following questions:
- •6. Match the first part (1-7) of the sentence with the second part (a-g) :
- •7. Read the supplementary text, translate and entitle it:
- •The scheme of rendering the text
- •In conclusion the author … The article ends with…
- •As far as I know already…
- •I’ve read before many/some/articles on the topic.
- •6. This information is useful for…
8. Render the text: An antenna
9. Work in pairs. Compare the two kinds of antennas.
UNIT 7
Pre-text exercises:
Fill in the blanks confusing words and memorize them: do, make
1. They're … a lot of noise, but so far they haven't … any progress. 2. The company is … a large profit, but in the meantime they're … a lot of damage to the environment. 3. She was asked to …a quick speech, but she took her time. 4. After we've … our homework, I think we should … the washing up. 5. She told me to take a seat, and then went to … some phone calls.6. Taking a test is a bit like … a crossword: you finish it eventually! 7.The policeman took my name and address, and … a few notes.8. We had to … a lot of work before we began to… any money.9. You really should take my advice and hire somebody to … your ironing, washing and other housework. 10. After I had made the bed, he lay down and took his medicine.
2. Find the Ukrainian equivalents for the following English words and word
combinations :
a) emit light, amplification, emission, a narrow beam, a high irradiance, low divergence, a large distance, the output coupler, inversion
b) підсилення, посилення; випромінювати світло; низьке розходження, відхилення; виділення, поширення, випромінювання; порушення, перекручення; вузький пучок; високе сяяння, випромінювання; велика відстань; вивідний зчеплюваний пристрій;
3. Which of these words from the list are similar in your language? Do they mean the same?
A laser, radiation, process, to stimulate, photon, base, limit, order, to produce, position, optical, correct, energy, material, to concentrate, original, humorously
4. Read the text and translate it: a Laser
A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation. The emitted laser light is notable for its high degree of spatial and temporal coherence. Spatial coherence typically is expressed through the output being a narrow beam which is diffraction-limited, often a so-called "pencil beam."
Laser beams can be focused to very tiny spots, achieving a very high irradiance. Or they can be launched into a beam of very low divergence in order to concentrate their power at a large distance. Temporal coherence implies a polarized wave at a single frequency whose phase is correlated over a relatively large distance along the beam. A beam produced by a thermal or other incoherent light source has an instantaneous amplitude and phase which vary randomly with respect to time and position, and thus a very short coherence length.
A laser which produces light by itself is technically an optical oscillator rather than an optical amplifier as suggested by the acronym. It has been humorously noted that the acronym LOSER, for "light oscillation by stimulated emission of radiation," would have been more correct. With the widespread use of the original acronym as a common noun, actual optical amplifiers have come to be referred to as "laser amplifiers", notwithstanding the apparent redundancy in that designation.
A laser consists of a gain medium inside a highly reflective optical cavity, as well as a means to supply energy to the gain medium. The gain medium is a material with properties that allow it to amplify light by stimulated emission. In its simplest form, a cavity consists of two mirrors arranged such that light bounces back and forth, each time passing through the gain medium. Typically one of the two mirrors, the output coupler, is partially transparent. The output laser beam is emitted through this mirror. Light of a specific wavelength that passes through the gain medium is amplified (increases in power); the surrounding mirrors ensure that most of the light makes many passes through the gain medium, being amplified repeatedly. Part of the light that is between the mirrors passes through the partially transparent mirror and escapes as a beam of light. The process of supplying the energy required for the amplification is called pumping.
The energy is typically supplied as an electrical current or as light at a different wavelength. Such light may be provided by a flash lamp or perhaps another laser. Most practical lasers contain additional elements that affect properties such as the wavelength of the emitted light and the shape of the beam. The gain medium of a laser is a material of controlled purity, size, concentration, and shape, which amplifies the beam by the process of stimulated emission. It can be of any state: gas, liquid, solid or plasma. The gain medium absorbs pump energy, which raises some electrons into higher-energy quantum states. Particles can interact with light by either absorbing or emitting photons. Emission can be spontaneous or stimulated. In the latter case, the photon is emitted in the same direction as the light that is passing by. When the number of particles in one excited state exceeds the number of particles in some lower-energy state, population inversion is achieved and the amount of stimulated emission due to light that passes through is larger than the amount of absorption. Hence, the light is amplified. By itself, this makes an optical amplifier. When an optical amplifier is placed inside a resonant optical cavity, one obtains a laser.
Post-text exercises: