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प्रश्न
A blackbody does not
(a) emit radiation
(b) absorb radiation
(c) reflect radiation
(d) refract radiation
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उत्तर
(c) reflect radiation
(d) refract radiation
A black body is an ideal concept. A black body is the one that absorbs all the radiation incident on it. So, a black body does not reflect and refract radiation.
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संबंधित प्रश्न
Draw a neat labelled diagram for Ferry's perfectly black body.
Show graphical representation of energy distribution spectrum of perfectly black body.
When electron in hydrogen atom jumps from second orbit to first orbit, the wavelength of radiation emitted is λ. When electron jumps from third orbit to first orbit, the wavelength of emitted radiation would be _______.
(A)`27/32lambda`
(B)`32/27lambda`
(C)`2/3lambda`
(D)`3/2lambda`
Find the wavelength at which a black body radiates maximum energy, if its temperature is 427°C.
(Wein’s constant b = 2.898 × 10-3 mK)
(A) 0.0414 × 10-6m
(B) 4.14 × 10-6m
(C) 41.4 × 10-6m
(D) 414 × 10-6m
Explain black body radiation spectrum in terms of wavelength
What is perfectly black body ? Explain Ferry’s black body.
The heat current is written as `(ΔQ)/(Δt)`. Why don't we write `(dQ)/dt?`
The normal body-temperature of a person is 97°F. Calculate the rate at which heat is flowing out of his body through the clothes assuming the following values. Room temperature = 47°F, surface of the body under clothes = 1.6 m2, conductivity of the cloth = 0.04 J s−1 m−1°C−1, thickness of the cloth = 0.5 cm.
A copper sphere is suspended in an evacuated chamber maintained at 300 K. The sphere is maintained at a constant temperature of 500 K by heating it electrically. A total of 210 W of electric power is needed to do it. When the surface of the copper sphere is completely blackened, 700 W is needed to maintain the same temperature of the sphere. Calculate the emissivity of copper.
A body cools down from 50°C to 45°C in 5 mintues and to 40°C in another 8 minutes. Find the temperature of the surrounding.
A hot body placed in a surrounding of temperature θ0 obeys Newton's law of cooling `(d theta)/(dt) = -K(theta - theta_0)` . Its temperature at t = 0 is θ1. The specific heat capacity of the body is sand its mass is m. Find (a) the maximum heat that the body can lose and (b) the time starting from t = 0 in which it will lose 90% of this maximum heat.
Which of the following is an example of an ideal black body?
Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region?
