If a black body is heated from 27°C to 927°C. then the ratio of radiation emitted will be
You are given a sphere, a cube and a thin circular plate, all made from copper and all having the same mass. If they are heated to a temperature of 200°C, then which are of them will cool fasted? |
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A body cools from 100°C to 70°C in 8 minutes. If the room temperature is 15°C and assuming Newton’s law of cooling holds good, then time required for the body to cool from 70°C to 40°C is |
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Heat energy received by the earth from the sun is due to |
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Two stars A and B radiate maximum energy at 3600Å and 3600Å respectively. Then the ratio of absolute temperatures of A and B is |
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In which process the rate of transfer of heat is maximum? |
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Solar radiation emitted by sun resembles that emitted by a black body at a temperature of 6000 K. maximum intensity is emitted at a wavelength of about 4800 Å. if the sun were cooled down from 6000 K to 3000 K, then the peak intensity would occur at a wavelength of |
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Emissivity of perfectly black body is |
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Absorptive power of perfectly black body is |
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The earth intercepts approximately one billionth of the power radiated by the sun. if the surface temperature of the sun were to drop by a factor of 2, the average radiant energy incident on earth per second would reduce by factor of |
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If the temperature of the sun is doubled. The rate of energy received on the earth will be increased by a factor of |
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