6. Put the verb into the correct form, Present Continuous or Present Simple.

1. This scientist (to be) never satisfied. He always (to complain).

2. In a vacuum-tube triode there (to be) three electrodes: a cathode, a plate and a grid.

3. When heated the cathode (to emit) electrons.

4. I see in fig.1 that the electrons (to flow) from the cathode to the plate.

5. The grid (to control) the flow of electrons when the device is switched on.

6. The closer the grid (to be) to the cathode, the more influence it has on the electron flow.

7. Look! The plate current (to decrease).

8. We are decreasing the negative voltage on the grid to 8 volts, and the current gradually (to increase).

9. Due to this property of a triode, it (can) be used for amplification.

10. Usually he (to work) as a physicist, but he (to read) lectures lately.

11. The number of electrons (to increase) very rapidly in this device.

12. It (to get) late. Let’s finish the experiment.

13. The grid (to be) placed between the cathode and the plate.

14. A: You (to work) hard today. B: Yes, I have a lot to do.

15. Even if a small negative voltage is applied to the grid, this (to result) in a large plate current.

Formulate the rules.

7. Form nouns from the following verbs using the suffix '-or', '-еr' and translate them:

amplify — усиливать; amplifier — ...

conduct — проводить (ток); conductor— ...

detect — детектировать, выпрямлять; detector — ...

control — управлять; controller — ...

divide — делить; divider — ...

learn — учить; learner — ...

operate — приводить в действие; operator — ...

heat — нагревать; heater — ...

insulate — изолировать; insulator — ...

emit — испускать; emitter — ...

direct — направлять; director — ...

use — использовать; user — ...

rectify — выпрямлять (ток); rectifier— ...

8. Choose the appropriate English equivalents

1. ближе— 1. close; 2. closer; 3.the closest

2. лучше— 1. good; 2. better; 3. the best

3. больше— 1. the most; 2. more; 3. Much

4. самый маленький— 1.small; 2. smaller; 3. the smallest

5. самый большой— 1. the largest; 2. large; 3. larger

6. выше—1. high; 2. higher; 3. the highest

Remember the spelling: big – bigger

9. Translate the following sentences. Mind the meaning of the highlighted words.

1. The farther the grid is from the cathode, the more the plate current is. 2. The wider the distance between the grid wires, the more the plate current is. 3. The higher the temperature, the lower the conductivity of a me­tallic conductor. 4. The lower the temperature, the better the conductivity of a metallic conductor.

5. The slower the electrons move, the easier it is to stop them and return them to the space charge. 6. The closer the grid is to the cathode, the more control it will have on elec­tron flow to the plate. 7. The more heavily the material is doped, the lower its electrical resistance will be. 8. The hotter the cathode becomes, the more electrons it emits per unit time (в единицу времени). 9. As the electrons move out into space, they form a cloud (облако) of negative charges. The larger this cloud becomes, the more opposition it offers to additional electrons leaving the cathode. 10. The more nega­tive the grid, the less the plate current will be. 9. The greater the load resistance of a tube amplifier, the greater is the voltage amplification.

10. Translate

1. Start from the first component:

anode current; electron tube; large plate current; semicoductor device; small negative voltage; large negative voltage; gas-filled envelope

2. Start from the second component:

electron flow; current flow; potential increase

11. Translate the following sentences. Start your translation from an adverbial modifier of place.

1. There is one grid in a triode. 2. There are two grids in a tetrode. 3. There are three grids in a pentode. 4. There is no grid in a diode.

12. Match the following sentences with their translations

The third element is called "a grid".	Чем ближе сетка к катоду, тем больше у нее влияние на поток электронов.
It is placed between the cathode and the plate.	К сетке приложено низкое отрицательное напряжение.
The purpose of a grid is to control the flow of electrons.	Это приводит к возникновению большого анодного тока.
The closer the grid is to the cathode, the more influence it has on the electron flow.	Вакуумные триоды могут усиливать ток.
The more negative the grid, the less the plate current.	Третий элемент называется «сеткой».
A small negative voltage is applied to the grid.	Она помещается между катодом и анодом.
This results in a large plate current.	Назначение сетки - управлять потоком электронов.
Vacuum triodes can amplify current.	Чем более отрицательна сетка, тем меньше будет анодный ток.