Two conducting square plates 6.5 cm on a side and separated by 2.3 mm air gap (dielectric constant of air gap is assumed to be 1) is fully charged with a 12.0 V battery. The battery is then disconnected and a dielectric material of dielectric constant 2.3 is inserted.

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.