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Define emissivity....

Define emissivity.

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ICSE-THERMAL RADIATION -SHORT ANSWER QUESTIONS
  1. Mention four properties of thermal radiation.

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  2. ''The inside of Ferry's black body is blackened but nickel polished ou...

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  3. What is meant by temperature radiation ?

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  4. Name the factors on which the thermal radiation emitted by a hot body ...

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  5. Define emissivity.

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  6. What is the difference between absorptive power and spectural absorpti...

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  7. What is the difference between absorptive power and spectural absorpti...

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  8. What is the ralation connecting absorpative, reflecting and transmitti...

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  9. What is the significance of Kirchhoff's law ?

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  10. Explain the formation of Fraunhofer lines using Kirchhoff's law .

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  11. What is Stefan's constant ?

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  12. What is the difference between Stefan's law and Newton's law of coolin...

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  13. State Wien's displacement law. Why is it called so ?

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  14. Name the law which helps us to explain the distribution of energy in t...

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  15. Explain Prevost's theory of heat exchanges.

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  16. Which body will emit more radiation under the similar condition, a bla...

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  17. Which star is at a higher temperature, a red star or a blue star ?

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  18. Mention a method to measure the temperature of a star.

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  19. ''The earth is not in thermal equilibrium with the sun.'' Why ?

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  20. Mountaineers caught in a storm sometimes survive by digging a cave in ...

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