Measurement, Conversion and Control MCQs

Question 1

What device is similar to an RTD but has a negative temperature coefficient?

Accepted Answer

Thermistor

Answer

Strain gauge

Answer

Negative-type RTD

Answer

Thermocouple

Question 2

The resistive change of a strain gauge

Accepted Answer

is based on the gauge factor, but is typically less than an ohm

Answer

is based on the weight placed upon it, but can be many thousands of ohms

Answer

is usually no more than 100 omega.gif

Answer

has a positive temperature coefficient

Question 3

The silicon-controlled rectifier can be turned off

Accepted Answer

by forced commutation

Answer

by a negative gate pulse

Answer

with the off switch

Answer

when the breakover voltage is exceeded

Question 4

The output voltage of a typical thermocouple is

Accepted Answer

less than 100 mV

Answer

greater than 1 V

Answer

Thermocouples vary resistance, not voltage.

Answer

None of the above

Question 5

The connections to a thermocouple

Accepted Answer

can produce an unwanted thermocouple effect, which must be compensated for

Answer

produce an extra desirable thermocouple effect

Answer

must be protected, since high voltages are present

Answer

produce an extra desirable thermocouple effect and must be protected, since high voltages are present

Question 6

What is the zero-voltage switch used for?

Accepted Answer

To reduce radiation of high frequencies during turn-on of a high current to a load

Answer

To control low-voltage circuits

Answer

To provide power to a circuit when power is lost

Answer

For extremely low-voltage applications

Question 7

Temperature sensing can be achieved by the use of

Accepted Answer

All of the above

Answer

thermocouples

Answer

RTDs

Answer

thermistors

Question 8

The purpose of compensation for a thermocouple is

Accepted Answer

to cancel unwanted voltage output of a thermocouple

Answer

to decrease temperature sensitivityto

Answer

to increase voltage output

Answer

used for high-temperature circuits

Question 9

The change in value of an analog signal during the conversion process produces what is called the

Accepted Answer

quantization error

Answer

resolution error

Answer

Nyquist error

Answer

sampling error