Which of the following statements is correct?

  • A
    $A$ good absorber is a bad emitter.
  • B
    Every body absorbs and emits radiations at every temperature.
  • C
    The energy of radiations emitted from a black body is the same for all wavelengths.
  • D
    The law showing the relation of temperatures with the wavelength of maximum emission from an ideal black body is Planck's law.

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Similar Questions

An ideal black body at room temperature is thrown into a furnace. It is observed that:

About black body radiation, which one of the following is a $WRONG$ statement?

$A$ sphere,a cube,and a thin circular plate,all made of the same material and having the same mass,are heated to the same temperature of $200^{\circ} C$. When these are left in a room,which one reaches room temperature the fastest?

$A$ body,which emits radiations of all possible wavelengths,is known as

The filament of a light bulb has a surface area of $64 \ mm^2$. The filament can be considered as a black body at a temperature of $2500 \ K$,emitting radiation like a point source when viewed from afar. At night,the light bulb is observed from a distance of $100 \ m$. Assume the pupil of the observer's eye to be circular with a radius of $3 \ mm$. Then:
(Take Stefan-Boltzmann constant $= 5.67 \times 10^{-8} \ W \ m^{-2} \ K^{-4}$,Wien's displacement constant $= 2.90 \times 10^{-3} \ m \ K$,Planck's constant $= 6.63 \times 10^{-34} \ J \ s$,speed of light in vacuum $= 3.00 \times 10^8 \ m \ s^{-1}$)
$(A)$ The power radiated by the filament is in the range $642 \ W$ to $645 \ W$.
$(B)$ The radiated power entering into one eye of the observer is in the range $3.15 \times 10^{-8} \ W$ to $3.25 \times 10^{-8} \ W$.
$(C)$ The wavelength corresponding to the maximum intensity of light is $1160 \ nm$.
$(D)$ Taking the average wavelength of emitted radiation to be $1740 \ nm$,the total number of photons entering per second into one eye of the observer is in the range $2.75 \times 10^{11}$ to $2.85 \times 10^{11}$.

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