[填空题]
A Carnot Cycle heat engine operates between temperatures of $700\,K$ and $300\,K$. The monatomic gas inside the engine undergoes four thermal processes:
$A→B$ isothermal expansion
$B→C$ adiabatic expansion
$C→D$ isothermal compression
$D→A$ adiabatic compression.
On the graph below, sketch the variation of pressure P of the gas with the volume of the gas. Use arrows to show the direction of the process. (There is no need to add values to the axes)
2.At the beginning of the adiabatic expansion, the volume of the gas is $2.2\times10^{−2}\,m^3$. During the expansion, the pressure of gas decreased from $9.2×10^5 \,Pa$ to $ 3.4×10^4 \,Pa$. Calculate the volume following this process.$V_2$= $m^3$
3.Determine the efficiency of the heat engine.η
4.In the adiabatic process, there is no heat transferred into or out of the system. Outline how adiabatic processes must be performed.
