Temperature

Question 1

What is temperature, SI unit, commonly used unit

Answer 1

Temperature is a measure of how hot or cold an object is. kelvin (K). Degrees Celsius

Question 2

What is heat, SI unit

Answer 2

Heat refers to the amount of thermal energy that is being transferred from a hotter to a colder region. Joule (J)

Question 3

What does a good thermometer consist off

Answer 3

-Easy to read scale

-Safe to use

-Responsive to temperature changes

-Sensitive to small temperature changes

-Able to measure the required range of temperatures

Question 4

Thermometer to use for measuring volume of a fixed mass of liquid

Answer 4

-Mercury-in-glass thermometer

-Alcohol-in-glass thermometer

Question 5

Thermometer to use for measuring electrical resistance of a piece of metal

Answer 5

-Resistance thermometer

Question 6

Thermometer to use for measuring electrical voltage or electromotive force

Answer 6

-Thermocouple thermometer

Question 7

Steps for calibrating a liquid-in-glass thermometer

Answer 7

Step 1: Choose an appropriate thermometric substance (mercury or alcohol)

Step 2: Choose two fixed points. (There are used as reference points to set up the scale for temperature measurement), (ice point - lower fixed point, steam point - upper fixed point)

Step 3: Divide the interval between the ice point and steam point into 100 equal parts. Each interval is 1 degree Celsius (change in length of mercury thread is proportionate to temperature change)

Question 8

How to determine the ice point

Answer 8

1. Immerse the bulb and the lower part of the thermometer stem into a funnel containing pure melting ice
2. When the mercury level in the thermometer stem is steady, make a mark (L0) at that level on the stem. This is the ice point.

Question 9

How to determine the steam point

Answer 9

1. Insert the thermometer into the apparatus. The bulb should be just above the boiling water
2. The stem of the thermometer should protrude from the top of the apparatus
3. When the mercury level in the thermometer stem remains steady, make a mark (L100) at that level on the stem. This is the steam point

Question 10

What is a resistance thermometer

Answer 10

-Consists of a platinum wire coiled around a piece of mica in a silica tube

-Resistance R of wire varies continuously with temperature over a range of values

Question 11

What is a thermocouple

Answer 11

-Consists of two wires made of different metals such as iron and copper

-The wire and joined to form two functions, which produce a small electromotive force when there is a temperature difference between them.