Home

What is the correct answer?

4

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

A. 0.45

B. 0.55

C. 0.40

D. 0.75

Correct Answer :

A. 0.45


Related Questions

A grey body is one whose absorptivity In free convection heat transfer transition from laminar to turbulent… The critical temperature is the temperature In regenerator type heat exchanger, heat transfer takes place by The amount of radiation mainly depends upon the Depending on the radiating properties, a body will be opaque when Metals are good conductors of heat because The value of Prandtl number for air is about In counter current flow heat exchanger, the logarithmic temperature difference… According to Newton's law of cooling, the heat transfer from a hot body… The total emissivity power is .defined as the total amount of radiation… Thermal conductivity of glass wool varies from sample to sample because… The transfer of heat by molecular collision is known as Thermal conductivity of wood depends on The time constant of a thermocouple is The transfer of heat by molecular collision is smallest in An ordinary passenger aircraft requires a cooling system of capacity. The logarithmic mean temperature difference (tm) is given by (where Δt1… The heat is transferred by conduction, convection and radiation in A steam pipe is to be lined with two layers of insulating materials of… The ratio of the emissive power and absorptive power of all bodies is… The thermal diffusivities for gases are generally The process of heat transfer from one particle of the fluid to another… When heat is transferred by molecular collision, it is referred to as… Thermal conductivity of water in general with rise in temperature Heat transfer in liquid and gases takes place by Fourier's law of heat conduction is (where Q = Amount of heat flow through… Sensible heat is the heat required to When α is absorptivity, ρ is reflectivity and τ is transmissivity,… The heat transfer from a hot body to a cold body is directly proportional…