Match the temperature of a black body given in List-I with an appropriate statement in List-II, and choose the correct option. [Given: Wien’s constant as 2.9 × 10−3 m-K and βπ π = 1.24 × 10−6 V-m] List-I List-II (P) 2000 K (1) The radiation at peak wavelength can lead to emission of photoelectrons from a metal of work function 4 eV. (Q) 3000 K (2) The radiation at peak wavelength is visible to human eye. (R) 5000 K (3) The radiation at peak emission wavelength will result in the widest central maximum of a single slit diffraction. (S) 10000 K (4) The power emitted per unit area is 1/16 of that emitted by a blackbody at temperature 6000 K. (5) The radiation at peak emission wavelength can be used to image human bones. (A) π → 3,π → 5, π → 2, π → 3 (B) π → 3,π → 2, π → 4, π → 1 (C) π → 3,π → 4, π → 2, π → 1 (D) π → 1,π → 2, π → 5, π → 3
To solve this problem, we need to match the temperature of a black body given in List-I with the appropriate statement in List-II using Wien's displacement law and the given constants.
Step 1: Understand Wien's Displacement Law
Wien's displacement law states that the wavelength at which a black body emits the most radiation (peak wavelength, ) is inversely proportional to its temperature :
where is Wien's constant.
Step 2: Calculate for Each Temperature
For :
This is in the infrared region.
For :
This is near the visible region but still mostly infrared.
For :
This is in the visible region (yellow light).
For :
This is in the ultraviolet region.
Step 3: Match Each Temperature with the Correct Statement
:
The peak wavelength is 1450 nm (infrared). This does not match any of the statements directly, but it is closest to (3) because infrared radiation can result in a wide central maximum in diffraction.
:
The peak wavelength is 967 nm (near infrared). This does not match any statement directly, but it is closest to (4) because the power emitted per unit area at 3000 K is less than at 6000 K.
:
The peak wavelength is 580 nm (visible). This matches (2) because the radiation is visible to the human eye.
:
The peak wavelength is 290 nm (ultraviolet). This matches (1) because ultraviolet radiation can emit photoelectrons from a metal with a work function of 4 eV.
Step 4: Choose the Correct Option
Based on the above analysis:
The correct option is (C):
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