Points to Remember, Glossary, Concept Map

Points to Remember

• Heat is a form of energy which is transferred from one part to another part of a substance.

• Heat transfer causes expansion, increases temperature and changes the state of the substance.

• When thermal energy is supplied to a solid, the atoms or molecules present in it gain energy and vibrate more vigorously about their fixed positions, forcing each other further apart.

• Melting, vapourisation, sublimation, condensation, freezing and deposition are the change of states that take place due to heat energy.

• Heat transfer takes place in three ways: conduction, convection and radiation.

• Conduction occurs in solids, convection in liquids and gases, and radiation takes place in vaccum.

• Capacity of substances to gain or loose heat energy is determined by three factors: mass of the substance, change in temperature and nature of the substance.

• There are three scales to measure temperature: Celcius scale, Fahrenheit scale and Kelvin scale.

• Calorimeter measures the heat capacity of water.

GLOSSARY

1. Calorimeter A device which measures the heat capacity of liquids.

2. Calorimetry The technique used to measure the amount of heat involved in a physical or a chemical process.

3. Conduction The process of heat transfer in solids from a region of higher temperature to a region of lower temperature without the actual movement of molecules.

4. Convection The form of heat transfer from places of high temperature to places of low temperature by the actual movement of liquid or gas molecules.

5. Heat capacity Amount of heat energy required to raise the temperature of a ­substance by 1° C or 1 K.

6. Radiation The form of heat transfer from one place to another place in the form of electromagnetic waves.

7. Specific heat capacity Amount of heat energy required to raise the temperature of 1 kilogram of a substance by 1° C or 1 K.

8. Temperature Physical quantity which expresses whether an object is hot or cold.

9. Thermos flask An insulating storage vessel that keeps its content hotter or cooler than the surroundings for a longer time.

10. Thermostat A temperature sensing device that turns an appliance or circuit on or off when a particular temperature is reached in it.

REFERENCE BOOKS

1. Fundamentals of Statistical and Thermal Physics - F.Reif

2. Statistical Thermodynamics and Microscale Thermo -physics - Carey

3. Heat, Thermodynamics and Statistical Physics - BrijLal and Dr. N. Subramaniyam

4.Thermodynamics and an Introduction to Thermos-statistics byHerbert Hallen

5.Fundamentals of Engineering Thermo dynamics by Michael Moran

INTERNET RESOURCES

https://w w w. explainthatstuf f . com/ thermostats.html

https://youtu.be/8-nLHWpgDsM

https://youtu.be/rYwgsF_haAg

https://youtu.be/EwzkYTfHFbo

Concept Map

ICT CORNER

Heat

Through this activity you will learn about heat energy through Interactive games.

Step 1 Open the Browser and type the URL given below

Step 2 You can see lot of games about heat energy.

Step 3 For example, click “Heat Energy match it” game. You will see the match words in the screen. Play and learn about heat energy.

Step 4 Likewise you can explore all the games.

Browse in the link:

https://www.learninggamesforkids.com/heat-energy-games.html