temperature Flashcards by Sophie Berens

Which of the following is not a temperature unit?

a. Kelvin

b. Rankine

c. Centigrade

d. Fahrenheit

e. Each answer is right

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0 Deg Celsius, corresponds to which of the following units

a. 32 Deg F

b. 273 K

c. 492 Deg R

d. all answers are right

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Kelvin temperature scale was originally related to:

a. All answer are right

b. Celsius temperature scale

c. Fahrenheit temperature scale

d. Rankine temperature scale

b. Celsius temperature scale

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Rankine temperature scale was originally related to:

a. Kelvin temperature scale

b. None of the answers is right

c. Celsius temperature scale

d. Fahrenheit temperature scale

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Which of the following temperature scale has only positive values:

a. Celsius temperature scale

b. Rankine temperature scale

c. Fahrenheit temperature scale

d. Kelvin temperature scale

b. Rankine temperature scale

d. Kelvin temperature scale

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A resistance temperature detector is:

a. A temperature detector that changes its resistance value as temperature increases or decreases.

b. An electrical element that converts changes in temperature to a voltage signal by measurement of resistance

c. Al answers are correct

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The best suited metals for RTDs have the following properties:

a. Stable with a given range of temperature

b. Have a good reproducibility

c. All answers are correct

d. Pure

c. All answers are correct

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The most used RTD metals are:

a. Aluminum

b. Nickel

c. All answers are correct

d. Platinum

e. Copper

b. Nickel

d. Platinum

e. Copper

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Wheatstone bridge is used to convert temperature into:

a. All answers are correct

b. Resistance

c. Current

d. Voltage

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Wheatstone bridge is balanced when a voltmeter or an ammeter is reading:

a. Negative values

b. Positive values

c. A zero value

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Wheatstone bridge has :

a. Two known and two unknown resistors

b. Four unknown resistors

c. One unknown resistor that represent the RTD

d. Three known resistors and one unknown resistor

c. One unknown resistor that represent the RTD

d. Three known resistors and one unknown resistor

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Question text
A 4-20 mA signal can be generated from a Wheatstone bridge if:

a. All answers are correct

b. A transducer replaces the RTD in the bridge.

c. A transducer replaces the voltmeter in the bridge

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If the RTD in a Wheatstone bridge is shorted, this indicates a:

a. Low temperature

b. High temperature

c. No answer is correct

a. Low temperature

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If the RTD in a Wheatstone bridge is open, this indicates:

a. Low temperature

b. high temperature

c. no answer is correct

b. high temperature

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Some problems with RTDs are :

a. Lead wires

b. Slow response time due to its large surface area

c. Self-heating

d. Low sensitivity

a. Lead wires

b. Slow response time due to its large surface area

c. Self-heating

d. Low sensitivity

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Which of the following RTD configuration(s) doesn’t/ ( don’t) induce any error in temperature readings?

a. Two wire RTD

b. Four wire RTD

c. All answers are correct

d. Three wire RTD

b. Four wire RTD

d. Three wire RTD

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A thermistor is a temperature element that:

a. Can increase its resistance as temperature increases

b. Has a resistance that changes in a non-linear relationship with temperature

c. Can decrease its resistance as temperature increases

d. None of the answers is correct

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a. Can increase its resistance as temperature increases

b. Has a resistance that changes in a non-linear relationship with temperature

c. Can decrease its resistance as temperature increases

Thermistors :

a. Are less sensitive to lead resistance

b. Have fast response

c. Have high sensitivity

d. Are very accurate

e. No answer is correct

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a. Are less sensitive to lead resistance

b. Have fast response

c. Have high sensitivity

d. Are very accurate

When two dissimilar wires are connected together at one end to form a junction and heated at that joint:

a. All answers are correct

b. A DC voltage is generated across them

c. A current is generated across them

d. An alternative voltage is generated across them

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b. A DC voltage is generated across them

The Seebeck effect is :

a. Current generated between two thermocouples connected back to back , when one of them is heated.

b. The voltage generated across two dissimilar wires when their junction is heated.

c. The voltage generated across a thermocouple

d. all answers are correct

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a. Current generated between two thermocouples connected back to back , when one of them is heated.

Different thermocouples handle different temperature ranges depending on:

a. All answers are correct

b. wire length

c. Wire size

d. Metals they are made of.

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d. Metals they are made of.

When measuring a voltage across a (T) type thermocouple leads sitting on a surface of a table inside a laboratory, you will see a zero voltage across it, this is because :

a. the thermocouple junction and the thermocouple leads are at the same temperature.

b. The thermocouple wires and the voltmeter leads are not of the same metal type

c. there is an electromagnetic interference around the thermocouple

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a. the thermocouple junction and the thermocouple leads are at the same temperature.

Ice bath and compensation circuit are used to:

a. All answers are correct

b. Eliminate the voltage created by the reference junction

c. Eliminate the effect of the junction created by measurement leads wires and the thermocouple wires.

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a. All answers are correct

A thermopile is :

a. all answers are correct

b. used to measure extremely low temperatures

c. a series of thermocouples connected in series to provide a high voltage output reading

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a. all answers are correct

Thermo wells are used to : a. All answers are correct b. protect the thermocouple from hazardous process fluid c. measure the process temperature d. prevent stopping the process when changing the thermocouple

b. protect the thermocouple from hazardous process fluid d. prevent stopping the process when changing the thermocouple

The only drawback of a thermo well is : a. that it has a long response time b. that heat has to go through the thermo well before reaching the temperature sensor. c. that it takes a long time delay for temperature reading d. All answers are correct

d. All answers are correct

Some advantages of thermocouples over other temperature sensors are: a. cheap b. rugged c. operate over a wide temperature range d. self powered ( don't need external power supply )

a. cheap b. rugged d. self powered ( don't need external power supply )

Thermocouples are not convenient in situations where : a. strong electromagnetic and radio frequency interference exist. b. whole operating range is needed c. high sensitivity is required d. all answers are correct

d. all answers are correct

Facts about thermocouples: a. Noise can induce errors in them b. All answers are correct c. They always generate mVolts d. They have small sensitivity

b. All answers are correct

When a thermocouple is open due to a cut in it, this fault will indicate : a. no answer is correct b. a low temperature reading c. a high temperature reading

c. a high temperature reading

When a thermocouple is shorted due to a fault, this will indicate: a. no answer is correct b. a high temperature reading c. a low temperature reading

c. a low temperature reading

Which of the following temperature element has the highest sensitivity? a. RTD b. thermistor c. Thermocouple

b. thermistor

The length of a pressure spring thermometer can go up to: a. 100 m b. 50 m c. 20 m

a. 100 m

Bimetallic thermometers operate on the following principle: a. The ends of two dissimilar metals are connected to a pointer to indicate temperature. b. Two dissimilar metals have different thermal expansion, hence they can flex out or in as temperature changes. c. All answers are correct d. If two dissimilar metals are joined together along their length, they expand and form an arc when temperature changes.

c. All answers are correct

Bimetallic strip is a type of temperature measuring device that is : a. All answers are correct b. Used in ON_OFF control c. Relatively inaccurate d. Slow in response. e. Not used to give remote temperature indication.

a. All answers are correct

Which of the following is a temperature indicator? a. All answers are correct b. Liquid in glass thermometer c. Bimetallic thermometer d. Pressure spring thermometer

a. All answers are correct

The liquid in a glass temperature indicator depends on: a. The volume thermal expansion of the liquid b. all answers are correct c. The linear thermal expansion of the liquid

b. all answers are correct

The pressure spring thermometer is made of: a. A bulb and a tube containing a high thermal coefficient expansion substance. b. A low coefficient thermal expansion bulb with a long metal tube. c. A metal tube terminated with a spiral Bourdon tube pressure gauge whose scale is in degrees. d. All answers are correct

d. All answers are correct

Pressure spring thermometer can be: a. Vapor filled b. All answers are correct c. Gas filled d. Liquid filled

b. All answers are correct

Liquid filled pressure spring works on the principle as the liquid in glass thermometer except that when the liquid expands, it drives a Bourdon tube : True False

True

temperature Flashcards

(40 cards)