1. Argon in a light bulb is at 90 kPa, 20?C when it is turned on and electricity input now heats it to 60?C. Find the entropy increase of the argon gas.
2. We wish to obtain a supply of cold helium gas by applying the following technique. Helium contained in a cylinder under ambient conditions, 100 kPa, 20?C, is compressed in a reversible isothermal process to 600 kPa, after which the gas is expanded back to 100 kPa in a reversible adiabatic process.
a. Show the process on a T-s diagram.
b. Calculate the final temperature and the network per kilogram of helium.