Which of the following P-V diagram represent the graph of isometric process?

Which of the following P-V diagrams best represents an isothermal process?

Which of the accompanying P-V diagrams best represents an isothermal process ?

An ideal gas is subjected to a cyclic process ABCD as depicted in the P-V diagram given below Which of the following curves represents the equivalent cyclic process?

Which of the following P-V curve best represents. As isothermal process?

Which of the following P-V curve best represents. As isothermal process?