253. Choose the suitable general question for the sentence:

There are 100s of different kinds of radio tubes.

a) Were there 100s of different kinds of radio tubes?

b) Do there 100s of different kinds of radio tubes?

c) Are there 100s of different kinds of radio tubes?

d) Did there 100s of different kinds of radio tubes?

254. Choose the suitable words:

A triode with an electrode placed between the grid and anode is called … .

a) pentode

b) tetrode

c) diode

d) triode

255. Choose the suitable answer:

The special device that convert ac to dc is called … .

a) amplifier

b) rectifier

c) transformer

d) generator

256. Choose the necessary word:

The resistance is the … of a conductor.

a) component

b) property

c) feature

d) points

257. Complete the sentence with necessary articles:

When an emf is applied … the ends … a wire the free electrons move … one direction … the circuit.

a) for, of, from, at

b) with, for, of, in

c) of, from, at, to

d) to, of, in, in

258. Choose the necessary word:

The engineer ….. the capacity of the condenser.

a) produces

b) increases

c) measures

d) develops

259. Choose the suitable word for sentence:

In the dc motor the current flows into the armature … .

a) coil

b) winding

c) core

d) case

260.Complete the sentence with necessary word:

The commutator and brushes of the dc generator … the current.

a) amplify

b) produce

c) rectify

d) increase

261. Complete the sentence with necessary words:

A … is a body or substance which cannot carry electrons easily.

a) conductor

b) insulator

c) nonconductor

d) semiconductor

262. Choose the suitable words:

The … is an elaboration of the diode.

a) pentode

b) tetrode

c) diode

d) triode

263. Choose the right answer:

We may define the difference in voltage between 2 points in an electrical circuit as the … … .

a) difference in potential

b) difference in voltage

c) difference in resistance

d) difference in pressure

264. Put the necessary prepositions:

The readiness … which electric charge passes … one body the another … a connecting medium.

a) of, in, across

b) to, from, due to

c) from, in, for

d) with, from, trough

265. Choose the suitable general question for the sentence:

The HMG doesn’t have a time limit for operation.

a) Was the HMG a time limit for operation?

b) Does the HMG have a time limit for operation?

c) Is the HMG have a time limit for operation?

d) Did the HMG have a time limit for operation?

266. Choose the suitable answer:

The … is a device capable of producing an output signal conforming to an input signal, but at a higher power level.

a) amplifier

b) rectifier

c) transformer

d) generator

267.Complete the sentence with necessary word:

By means of the rectifier … ac into a pulsating dc

a) amplifies

b) produces

c) converts

d) increases

268. Choose the right answer:

The main protective device of the consumer circuits are … .

a) fuse boxes

b) automatic circuit breaker

c) plug connector

d) tie relay

269. Translate the following word combinations into English:

Сравнительно высокое напряжение в цепи

a) rather big voltage in the coil

b) comparatively high voltage in the circuit

c) enough a lot of power in the phase

d) essential few violence in the mains

270. Choose the sentence with right order:

captain/transfer/usually/the(2)/bus (2)/left/ gets/ from/power/ ac.

a) The transfer bus captain usually gets power from the ac left bus.

b) The bus usually gets power from the left captain transfer ac bus.

c) The captain transfer bus usually gets power from the left ac bus.

d) The power gets from the captain transfer bus usually left ac bus.