The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as

Related MCQs

• 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 rate of radiant energy, which is emitted by a surface at any temperature and in small wavelength is found from the known rate of energy, which under the same condition would be emitted from a black surface by multiplying with the absorptivity. Above enunciation is known as
• In a laboratory test run, the rate of drying was found to be 0.5 x 10-3 kg/m2 .s, when the moisture content reduced from 0.4 to 0.1 on dry basis. The critical moisture content of the material is 0.08 on a dry basis. A tray dryer is used to dry 100 kg (dry basis) of the same material under identical conditions. The surface area of the material is 0.04 m2 /kg of dry solid. The time required (in seconds) to reduce the moisture content of the solids from 0.3 to 0.2 (dry basis) is
• The rate of heat flow between a solid wall and a fluid (in contact with a solid wall) is given by
• Solid angle subtended by the finite surface at the radiating element is
• A dimensionless number which is the ratio of mass heat flow rate to the heat flow rate by conduction under a unit temperature gradient and through a thickness L is known as
• Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer across an equal area held at the
• The rate of emission of radiation by a body does not depend upon the
• The coefficient of linear expansion of a solid is L. The volume V of a cube of this solid on being heated by 1?C will change by
• Which of the following is the most controlling factor for the rate of bubble detachment from the hot solid surface?