Two sphere of same material have radii r1 and r2. They are heated to same temperature and kept in same enclosure at low temperature their rates of loss of heat are in the ratio
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If the wavelengths of maximum intensity of radiation emitted by the moon and the sun are 10–4 m and 0.5 × 10–6m respectively, then the ratio of their temperature is |
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The maximum wavelength of radiation emitted by a black body at 1227°C is λm. What is its maximum wavelength at 2227°C? |
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A black body radiates energy at the rate of E watt m–2 at a temperature of T Kelvin. When the temperature is reduced to T/2 Kelvin, the radiant energy will become |
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A body at higher temperature T K radiates heat at a rate which is proportional to |
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According to Prevost’s theory of heat exchange, the heat exchange shops at |
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The best ideal black body is |
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The rate of cooling of a body is 0.5°C/minute, when the body is 50°C above the surrounding. What is the rate of cooling if the body is 30°C above the surrounding? |
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Coefficient of transmission and coefficient of reflection for a given body are 0.22 and 0.74 respectively. Then, at a given temperature, the coefficient of emission for the body is |
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Wien’s constant units is |
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A body radiates heat at the rate of 4 cal/m2/s, when its temperature is 227°C. what is the heat radiated by the same body when its temperature is 727°C? |
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