Consider a 20 cm thick granite wall with a thermal conductivity of 2.79 W/mK. The temperature of left surface is 50°C and right surface is exposed to 22°C air with a convection heat transfer of 15W/m^2K. Neglecting radiation heat transfer, determine the heat flux through the wall.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?