4. (40 points) A closed chamber containing a monatomic ideal gas undergoes the thermodynamic cycle shown in the figure. The process ab is isothermal with a compression ratio of 10 (in other words, V. = V, /10 ). The process be is isochoric. The 02 process ca is adiabatic. Other than the a Compression ratio, you are not given any other specific numbers on the pV- P diagram. , 202 a) (28 points) What is the efficiency of the cycle (your answer should be a numerical P value)? Show all of your work. In addition, you must show where heat enters and leaves the engine. (Hint: Calculating the heat added or removed for each process may be helpful here.)