Class 9th Physics Unit 9 Transfer of Heat

physics 9th notes Chapter No 9

1. SI unit of Coefficient of linear & volume expansion is:


2. The SI unit of temperature is:


3. Transmission of heat from one body to another body by the interaction of atoms and electrons:


4. Quantity of heat that changes one kilogram of a of liquid into gas is called:


5. Black surfaces are:


6. Water is a:


7. Styrofoam is a:


8. Temperature is the:


9. Geysers work on the principle of:


10. Which one is (are) the insulator (s)?


11. Specific heat of water is:


12. Quantity of heat that changes one kilogram of a of solid into liquid is called:


13. Cause of land and sea breeze is:


14. Human normal body temperature of 37°C in Fahrenheit is:


15. Which of the following has highest specific heat?


16. Temperature of 30 °C in Fahrenheit is:


17. Which of the following is best for insulation?


18. The quantity of heat that causes 1K change in temperature in a substance of mass 1 Kg is called:


19. The device used to measure of the specific heat of an object is:


20. Climate of regions near sea shore remains moderate due to:


21. Unit of thermal conductivity is: 


22. The characteristic of unequal expansion of different metals is employed in a device known as:


23. Unit of latent heat is:


24. Latent heat of vaporization of water is:


25. The thermal conductivity of copper is:


26. Heat from sun reaches us by:


27. Unit of specific heat is:


28. Heat is a type of energy:


29. Ventilation in our houses is only possible due to:


30. Latent heat of fusion of ice is:


31. Linear expansion of a rod occur along —– dimension (s):


32. The thermal conductivity of glass is: 


33. β =


34. Feathers of the birds are:


35. The thermal conductivity of Aluminum is: 


36. The thermal conductivity of brick is: 


37. There are —– type of expansion take place in a liquid filled in a container:


38. The liquid used in thermometers is (are):


39. Volume expansion depends on:


40. Methods of transmission of heat are: 


41. The gases in the Earth’s atmosphere, which causes the greenhouse effect:


42. Thermostat is used in:


43. Global warming in the world is due to:


44. Fahrenheit equivalent of OK is:


45. Linear expansion depends on:


46. Thermostat works on the principle of:


47. Celsius equivalent of OK is:


48. Transfer of heat by the actual movement of molecules:


49. Ice is a (an):


50. All the bodies expand on heating:


51. Transmission of heat by waves without affecting medium on its way:


52. Boiling point of water in Fahrenheit is:


53. Shinning silvered surfaces are:


Short Questions

Define conduction.
Define convection with examples?
Define Greenhouse Effect.
Define Radiation.
Define rate of flow of heat write its formula and unit
Define thermal conductivity write its formula and unit.
Define transfer of heat write its methods?
Describe convection in water heating by putting a few pinky crystals in round   bottom flask.
Explain convection in seawater to support marine life.
Explain how the birds are able to fly for hours without flapping their wings and glider is able to rise by riding on thermal currents which are streams of hot air rising in the sky.
Explain the impact of the greenhouse on global warning.
Explain why Deserts soon get hot during the day and soon get cold after sunset?
Explain why Double walled glass vessel is used in thermos flask?
Explain why Land breeze blows from land towards sea?
Explains why a metal feels colder t touch than wood kept in a cold place?
How do land and sea breezes help to keep the temperature moderate in coastal areas?
How do thermals help birds to fly for hours without flapping their wings?
How does heat flow from hot to cold parts in metals so rapidly than non-metals?
How does heat reach us directly from a fireplace?
How does heat reach us from the sun?
How does the temperature in a greenhouse can be maintained?
How land and sea breezes are produced?
How various surfaces can be compared by a Leslie cube?
List the thermal conductivities of some substances?
List three names by which heat can be transfer from one to place to another place?
On which factors rate of radiation depends?
We wear black and dark coloured cloth in winter. Why?
We wear white and light coloured cloth in summer. Why?
What are Bad conductors or Insulator? Give examples?
What are Conductors? Give examples.
What causes a glider to remain in the air?
What do you know about convection currents in Air? Write down some uses.
What is gliding?
What is Global warming?
What is greenhouse effect?
What is meant by conduction?
What is meant by convection current?
What is the greenhouse effect?
Why a balloon inflated with hot air rises up?
Why conduction of heat does not take place in gases?
Why does a cup of hot tea become cold after sometimes?
Why does a glass of chilled (frozen) water become hot after sometimes?
Why does sea breeze blow during the day? Why does land breeze blow in the night?
Why metals are good conductors of heat?
Why Styrofoam boxes are used to keep food hot or ice cream cold for a long time?
Why tea in a cup becomes cold earlier as compared to a teapot?
Why transfer of heat in fluids takes place by convention?

Long Questions


Define Radiation. How does heat reach us from the sun? Explain Radiation. Radiation
Derive the relation for thermal conductivity of a substance?
Describe in terms of molecules and electrons how heat transfer occurs in solids.
Describe the users of conductors and non-conductors with examples?
Explain application and consequences of radiation?
Explain the energy transfer of a body by radiation does not require a material medium and rate of transfer is affected by:
Colour and texture of the surface
Surface temperature
Surface area
Explain the impact of greenhouse effect in global warming.
Explain the process of radiation?
How various surfaces can be compared by a Leslie cube?
Investigate the absorption of radiation by a black surface and silvery surface using Leslie cube. Also investigate the emission of radiation by a black surface and silvery surfaces using Leslie cube.
On what factors conduction of heat depend? And Define thermal conductivity.
The concrete roof of a house of thickness 20 cm has an area 200 m². The temperature inside the house is 15 °C and outside is 35°C. Find the rate at which thermal energy will be conducted through the roof. The value of k for concrete is 0.65 W m– 1 K– 1
What do you know about convection currents in Air? How land and sea breeze
What do you know about greenhouse effect? Also explain the global warming.
What is Conduction? Explain the process and write down it usage in our daily life.
What is convection? Explain the process.
What is Gliding? And what do you know about birds gliding?
What is Leslie cube? How various surfaces can be compared by Leslie cube?
What measures do you suggest conserving energy in houses?
Write down the uses of conductors and non — conductors.

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