Helium is used as the working fluid in a brayton cycle with regeneration. the pressure ratio of the cycle is 8, the compressor inlet temperature is 300 k, and the turbine inlet temperature is 1800 k. the effectiveness of the regenerator is 75 percent. determine the thermal efficiency and the required mass flow rate of helium for a net power output of 60 mw, assuming both the compressor and the turbine have an isentropic efficiency of (a) 100 percent and (b) 80 percent.

Ahouse has the following electrical appliance usage (1) single 40w lamp used for 4 hours per day (2) single 60w fan used for 12 hours per day (3) single 200w refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours find the solar power inverter size in watt with correction factor of 1.25.

The filament of an incandescent lamp has a temperature of 2000k. calculate the fraction of radiation emitted in the visible light band if the filament is approximated as blackbody

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?