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The spectral energy distribution for a body at temperature T is shown in figure. Now it the temperature of the body is increased

Heat Transfer ISRO Upload (1-51) images Q13

  1. λm will shift towards right
  2. λm will shift towards left
  3. The total energy emitted by the body will decrease
  4. λm will remain the same but Em will increase

Answer (Detailed Solution Below)

Option 2 : λm will shift towards left

Detailed Solution

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CONCEPT:

Wien's Displacement Law:        

  • According to Wien's law the product of wavelength corresponding to the maximum intensity of radiation and temperature of the body (in Kelvin) is constant, i.e.

λmT = b = constant

Where b = Wien's constant and has value 2.89 10-3 m-K.

EXPLANATION:

  • As the temperature of the body increases, the wavelength at which the spectral intensity (Eλ) is maximum shifts towards left. Therefore option 2 is correct.
  • Therefore it is also called Wien's displacement law.
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