Heat and Mass Transfer Radiation is the process of heat transfer in which heat flows from a ________, in a straight line, without affecting the intervening medium. Cold body to hot body Smaller body to larger body Hot body to cold body Larger body to smaller body Cold body to hot body Smaller body to larger body Hot body to cold body Larger body to smaller body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Emissivity Transmissivity Reflectivity Intensity of radiation Emissivity Transmissivity Reflectivity Intensity of radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be Two Four One Three Two Four One Three ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Kirchoff's law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a Red hot body Grey body Brilliant white polished body Black body Red hot body Grey body Brilliant white polished body Black body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.4 0.45 0.55 0.75 0.4 0.45 0.55 0.75 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is h₁ + h₂ + h₃ None of these 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 h₁ + h₂ + h₃ None of these 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 ANSWER DOWNLOAD EXAMIANS APP
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