Choose the best alternatives 1, 2, 3, 4 or 5 to answer the questions

УТВЕРЖДАЮ

Проректор по учебной работе

профессор

_________________________

М.А. Иванов

«____» ____________ 2012 г.

ТЕСТ К ЭКЗАМЕНУ

По учебной дисциплине

«Иностранный (английский) язык»

IV семестр

очно-заочный факультет

Для студентов специальности:

200101.65.02 Контрольно-измерительные приборы и системы

Вариант 2

Составители: доц. Р.Д.Кирпичников, каф.ИЯ

ст. преподаватель С.П. Егоров, каф.ИЯ

Санкт-Петербург

I. БЛОК ЧТЕНИЯ

Read the text 1.

Choose the best alternatives 1, 2, 3, 4 or 5 to answer the questions.

An ammeter is a measuring instrument used to measure the flow of electric current in a circuit. Electric currents are measured in amperes, hence the name. The earliest design is the D'Arsonval galvanometer or moving coil ammeter. It uses magnetic deflection, where current passing through a coil causes the coil to move in a magnetic field. The voltage drop across the coil is kept to a minimum to minimize resistance across the ammeter in any circuit into which it is inserted. Moving iron ammeters use a piece or pieces of iron which move when acted upon by the electromagnetic force of a fixed coil of (usually heavy gauge) wire. This type of meter responds to both direct and alternating currents opposed to the moving coil ammeter, which works on direct current only. To measure larger currents, a resistor called a shunt is placed in parallel with the meter. Most of the current flows through the shunt, and only a small fraction flows through the meter. This allows the meter to measure large currents. Traditionally, the meter used with a shunt has a full-scale deflection (FSD) of 50mV, so shunts are typically designed to produce a voltage drop of 50mV when carrying their full

rated current. More modern ammeter designs are non-mechanical, or digital, and use an analog to digital converter (ADC) to measure the voltage across the shunt resistor. The ADC is read by a microcomputer that performs the calculations to display the current through the resistor.

№	Вопросы	Варианты ответов
1.	What is an ammeter used for?	1. To measure electric power. 2. To measure electric resistance. 3. To measure the flow of electric current. 4. To measure electric voltage. 5. To measure the shape of electric signals.
2.	Which is the right statement?	1. A magnetic field moves in the coil. 2. The coil doesn’t move in a magnetic field. 3. The current makes a magnetic field move. 4. The coil moves in a magnetic field. 5. The coil makes the current move.
3.	What has to be held to a minimum in an ammeter?	1. Voltage 2. Resistance 3. Circuit 4. Voltage drop 5. Magnetic field
4.	What is a shunt?	1. A kind of ammeter 2. A parallel current 3. A measured current 4. A resistor 5. A large current
5.	What do the shunts do?	1. They measure the current. 2. They stop the current from flowing. 3. They make most of the current flow through themselves. 4. They make the entire current flow through themselves. 5. They make a small fraction of current flow through themselves.
6.	50 mV is:	1. the minimal voltage applied to a shunt 2. a full-scale deflection of a meter 3. a voltage produced by a shunt 4. the maximum voltage of a shunt 5. a full-scale deflection of a shunt
7.	ADC is:	1. a kind of ammeter 2. a measuring device 3. a part of an ammeter 4. a kind of shunt 5. a kind of resistor
8.	How widely are non-mechanical ammeters used now?	1. rarely 2. never 3. from time to time 4. mainly 5. only in some specific industries
9.	What is the function of a microcomputer in the ammeter?	1. to measure the current 2. to control the ADC 3. to do calculations 4. to control the resistor 5. to switch the ammeter
10.	Are ammeters able to memorize the measured values?	1. Yes, but only certain models. 2. No, they are not. 3. No information provided. 4. Yes, when connected to an external storage unit. 5. Yes, but this function is not reliable.