Temperature

Question 0

What are fixed points?

Answer 0

2 temperatures that are easily and accurately reproducible.

Question 1

Define ‘Temperature’

Answer 1

Measure of degree of hotness of a body.

Question 2

How can temperature be converted into kelvin?

Answer 2

X degrees = (X+273)K

Question 3

What are some examples of thermometric properties?

Answer 3

1. Volume of fixed mass of liquid in a glad bulb.
2. Resistance of length of platinum wire.
3. Voltage of thermal couple.

Question 4

How do we find the lower fixed point of a mercury in glass thermometer?

Answer 4

1. Place bulb of thermometer in pure melting ice.

2. When mercury meniscus is steady, mark its position as 0 degrees.

Question 5

How do we find the upper fixed point of a mercury in glass thermometer?

Answer 5

1. Place bulb of thermometer in steam from pure water boiling at standard atmospheric pressure.
2. When mercury meniscus is steady, mark its position as 100 degrees.

Question 6

How do we calibrate a mercury in glass thermometer?

Answer 6

1. Find lower fixed point.
2. Find upper fixed point.
3. Divide distance between 0 degrees and 100 degrees mark into 100 equal divisions. Each division is 1 degree.

Question 7

How can the sensitivity of a mercury in glass thermometer be increased?

Answer 7

1. Using narrower capillary tube.

2. Using bigger mercury bulb.

Question 8

What does a thermocouple thermometer consists of?

Answer 8

Consists basically of 2 wires of different metals joined together at the ends to form 2 junctions. If the junctions are at different temperatures, a small e.m.f is produced.

Question 9

How does the thermocouple thermometer work?

Answer 9

1. One end of thermometer, known as cold junction, placed in melting ice at 0 degrees(ice point).
2. The other end, known as hot junction, is placed in object whose temperature is to be measured.

Question 10

How is the e.m.f produced in a thermocouple thermometer?

Answer 10

The e.m.f produced in a thermocouple is directly proportional to the temperature difference between the junctions.

Question 11

What is the thermometric property in a thermocouple thermometer?

Answer 11

Variation of the voltage generated between the cold and hot junctions of the thermocouple as the temperature difference between the 2 junctions increases.

Question 12

What are the advantages of using the thermocouple thermometer?

Answer 12

1. Able to measure wide range of temperatures, from -200 to 1700.
2. Very sensitive- able to detect small changes and able to respond fast.