Correct the sentences where necessary. Some of these sentences need a/an

1. Chemical elements may be added to intrinsic silicon to alter its conductivity.

2. Our lives would be very difficult without electricity.

3. Press a button and the small device, resembling in many ways table-top calculator, starts lesson.

4. Typical donor impurities for silicon are arsenic, phosphorus and antimony.

5. Experts from Paris institute have used an electronic photo camera to obtain scientific proof.

6. Who doesn’t want to learn a foreign language in two or three weeks?

7. Although paper is a poor conductor, it is by no means a perfect insulator.

8. Another use for a diode is to maintain a special voltage level for a signal.

9. Robot building has become rather large sphere in our days.

2. Complete the sentences using the following. Use the where necessary.

(the) materials (the) same (2) (the) electrons

(the) semiconductors (the) task (the) tube

1. A transistor may perform … function as a vacuum-tube triode.

2. One method of generating free electrons is to expose certain … to light.

3. One integrated circuit can carry out … of several hundred transistors.

4. … are considered to be widely used in rectifiers, radio receivers, high-frequency technique, lasers, etc.

5. A grid placed near the space charge is better able to stop … than one placed farther away.

6. When a triode operates, the cathode emits ….

7. As the positive voltage of the plate becomes greater with respect to the cathode, current flow through … increases.

Fill in the gaps with articles a/an, the where necessary.

1. … special liquid was introduced into certain points of … body and … photo camera recoded … gamma rays released by … liquid.

2. … centre with up-to-date … automation ensures … safe shipping in northwestern sector of … Black Sea.

3. … new device known as LENAR has been patented in … United States, … France, … Japan, … Federal Republic of Germany and … Canada.

4. … phenomenon is of … great scientific and practical significance, offering … deeper insight into … processes which take place in … crystals under … influence of … electric field.

5. … most important fact to remember about … diode is how much … current it will pass with … given amount of … plate voltage.

4. Translate the sentences from Russian into English. Mind the usage of articles.

1. Чем дальше сетка находится от катода, тем больше анодный ток.

2. Чем шире расстояние между проволочками сетки, тем больше анодный ток.

3. Чем выше температура, тем ниже проводимость металлического проводника.

4. Чем ниже температура, тем лучше проводимость металлического проводника.