3. 4. Translate the following sentences. Pay attention to the meanings of “one”/”ones”.

1. A direct current is one which always flows in the same direction, although it may vary in magnitude.

3. An alternating current is one which varies its direction periodically.

4. This current flows first in one direction and then in the other and the time of each variation is constant.

5. When power is applied one transistor will always conduct a little more heavily than the other.

6. The light-sensitive surface is usually provided with two leads, either one of which may be used.

7. One should know the difference between analog and digital computers.

5. Translate the following sentences. Pay attention on to the use of correlative coordination: both…and; either…or; neither …nor:

1. Both chemical and mechanical energy can be transformed into electricity.

2. Between conductors and insulators are many materials which are neither good conductors, nor acceptable insulators.

3. If a battery is added in series with a clipping there may be either above or below zero voltage, depending on the polarity of the battery.

4. A quantity meter has a current circuit only; an energy meter has both current and voltage circuit.

5. The beam emerging from the electron gun may be deflected either electro- statically or magnetically.

6. Both the information to be processed and the instructions to process it are stored in the memory cells of the computer.

7. Radiation sensors are available as either electron tube devices known as phototubes or solid state semiconductor devices known as photocells.

XVI. Complex Sentences. Zero “that”- clauses.

1. Translate the sentences with zero that- and which- clauses:

A. Kurchatov understood it was considerably easier to use the nuclear chain reaction for destruction than for the production of energy used for homes and factories. He was sure there was a way to control this reaction and release it in small doses and he found it. We know his ideas helped the development of thermonuclear research.

B. 1. A few pounds of uranium 235 can supply a medium – sized town with all the electricity it needs during a whole year.

2. The atomic weight of an atom is the number of protons and neutrons it contains.

3. The phenomenon Roentgen discovered is widely used in medicine.

4. This is a type of reaction you will easily understand.

5. One of the problems I. Kurchatov worked at was the problem of mastering controlled thermonuclear reactions.

6. Einstein gave an entirely new idea of the world we live in.

7. The problem we are dealing with is very important for our laboratory.

8. The substance they had to work with had unpleasant odour.

9. That portion of mechanics we dealt with at our last lesson is known as statics.

10. Today we know atoms are neither unchangeable nor indivisible.

11. The material the apparatus is made of is a good non-conductor of heat.

12. It is known one horse power equals 746 watts.

13. The rate a machine does work at is measured in horse power or kilowatts.

14. Every engineer knows the units of work are important and depend upon the units chosen for force applied and distance moved.

15. Heat is the energy a body possesses owing to the fact that its molecules are in motion.

16. Substances that transform the energy they absorb into light without becoming heated, are called luminofores, and the light they radiate – luminescence.

17. The action of the force pressure depends not only on its value, but also on the area of the surface it acts upon.

18. The mineral the scientist was working with for a number of years was uranium and its compounds.

19. All the data the magazine referred to are based on the experiments carried out in our laboratory.

20. The particles all the different atoms consist of are neutrons, protons and electrons.