If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of

Related MCQs

• The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as
• According to Kirchoff’s law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a
• 200 kg of solids (on dry basis) is subjected to a drying process for a period of 5000 seconds. The drying occurs in the constant rate period with the drying rate as, Nc = 0.5 × 10-3 kg/m2 .s. The initial moisture content of the solid is 0.2 kg moisture/kg dry solid. The interfacial area available for drying is 4 m2 /1000 kg of dry solid. The moisture content at the end of the drying period is (in kg moisture/kg dry solid).
• The relation between the emissive and absorptive power of a surface is developed under
• The wavelength at which the maximum monochromatic emissive power occurs for a black body, is (where, T = absolute temperature of the black body).
• "The ratio of the total emissive power to the absorptivity for all bodies is same at ther-mal equilibrium". This is __________ law.
• The emissive power of a body depends upon its
• If the thermal conductivity of a wall material is independent of temperature, the steady state temperature distribution in the very large thin plane wall having steady, uniform surface temperature follows __________ law.
• A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The temperature at a distance 100 mm from the dipped end becomes 40°C at time, t = 200 s. The same temperature is achieved at a distance of 200 mm from the dipped end at time
• If the thermal conductivity of a wall material is independent of temperature, the steady state temperature distribution in the very large thin plane wall having steady, uniform surface temperature follows __________ law.