2. CONTENT
What is heat?
Hot and cold
Flow of heat energy
Concept of temperature
Measuring temperature
Scale of temperature
Reading a thermometer
Types of thermometer
a) clinical
b) laboratory
3. WHAT IS HEAT ?
Heat is a form of energy that can do work.
5. Hot and cold :
In our daily life we come across a number of objects. Some of them are
hot and some of them are cold .
1. You have a chilled bottle of cold drink and a glass of
boiling tea. Which of the two has more of heat energy in
it?
2. Which sense in your body helps you in learning
about cold, warm and hot?
3. Name some different forms of heat energy.
4. what is heat ?
5. Name some different forms of heat energy.
8. Observation:
Here we feel different in both hands. The hand
which was in hot water now feel cool in mixed
water; while the other hand feel hot in mixed
water.
Explanation:
Heat and cold are relative terms. For example,
40°C is hotter than 30°C but is colder than
50°C. A similar thing happens to our body and
hands. We detect cold and warm through the
same sensors present in our skin. Once our
hand is in hot water, it feels chilly when we place
the same hand to a slightly less hot mixture that
is a mixed solution.
9. Measurement Of Temperature :
• Temperature is measured by a device called
thermometer.
• Temperature is measured in degrees.
• Temperature is measured on two scales.
• Scale of temperature :
• a) celsius scale
• b) Fahrenheit scale
• °C is the symbol for the celsius scale.
• °F is the symbol for the fahrenheit scale.
• Thermometer is an instrument that is used to measure
temperature.
10. There are two scale of measurement of
temperature. These are :
1) Degree celsius ( ˚C )
2) Degree fahrenheit ( ˚F )
1) On a celsius scale , the freezing point of water is 0˚ C
whereas its boiling point is 100˚ C. So , this scale
calibrate from 0˚ to 100˚ C .
2) On a fahrenheit scale , the freezing point of water is
32˚ F whereas its boiling point is 212˚ F . So this scale
is calibrate from 32˚ F to 212˚ F .
