A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250 nm is ${{\rm{U}}_1}$ , at wavelength 500 nm is ${{\rm{U}}_2}$ and that at 1000 nm is ${{\rm{U}}_3}$ . Wien’s constant, ${\rm{b}}\, = \,2.88\, \times \,{10^6}\,{\rm{nmK}}{\rm{.}}$ Which of the following is correct?

${{\rm{U}}_1}\, > \,{{\rm{U}}_{\rm{2}}}$

${{\rm{U}}_1}\,{\rm{ = }}\,{\rm{0}}$

${{\rm{U}}_3}\,{\rm{ = }}\,{\rm{0}}$

${{\rm{U}}_2}\, > \,{{\rm{U}}_1}$

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NEET UG PHYSICS MCQ: THERMAL PROPERTIES OF MATTER

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A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250 nm is

{\mathrm{U}_1}

, at wavelength 500 nm is

{\mathrm{U}_2}

and that at 1000 nm is

{\mathrm{U}_3}

. Wien’s constant,

\mathrm{b}\, = \,2.88\, \times \,{10^6}\,\mathrm{nmK}\mathrm{.}

Which of the following is correct?

View answer and explanation

Correct option: C

{\mathrm{U}_1}\, > \,{\mathrm{U}_\mathrm{2}}

Option D (

{\mathrm{U}_2}\, > \,{\mathrm{U}_1}

) is correct because the wavelength of maximum emission shifts according to Wien's displacement law, and 500nm is closer to that wavelength than 250nm.

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