Heat and Mass Transfer If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called Absorptive power None of these Emissive power Emissivity Absorptive power None of these Emissive power Emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When absorptivity (α) = 1, reflectivity (ρ) = 0 and transmissivity (τ) = 0, then the body is said to be a Black body Opaque body White body Grey body Black body Opaque body White body Grey body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has maximum value of thermal conductivity? Copper Aluminium Brass Steel Copper Aluminium Brass Steel ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following property of air does not increase with rise in temperature? Density Thermal conductivity Dynamic viscosity Thermal diffusivity Density Thermal conductivity Dynamic viscosity Thermal diffusivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The critical radius is the insulation radius at which the resistance to heat flow is Minimum None of these Zero Maximum Minimum None of these Zero Maximum ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer, The better insulation must be put outside The better insulation must be put inside One should take into account the steam temperature before deciding as to which insulation is put where One could place either insulation on either side The better insulation must be put outside The better insulation must be put inside One should take into account the steam temperature before deciding as to which insulation is put where One could place either insulation on either side ANSWER DOWNLOAD EXAMIANS APP
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