Three separate reversible processes (1,2 and 3) are carried out with 1 mole of an ideal gas initially at STP. In these processes, the pressure ( P ) is measured while increasing any one of the quantities volume (V), temperature (T) and number of moles (n), keeping the other two constant. Plots of P (atm) versus X are found to be linear, where $\mathrm{X}=\mathrm{n}$ or $\mathrm{T}(\mathrm{K})$ or $1 / \mathrm{V}\left(\mathrm{lit}^{-1}\right)$. For the processes 1,2 and 3 , the numerical values of the slopes $m_1, m_2$ and $m_3$ of the P versus X plots are found to follow the order $m_1 \gt m_2 \gt m_3$, respectively. The correct statement(s) about these processes is/are

• Correct answer
  A

  work done is zero for process 3
• Correct answer
  B

  heat is completely converted into work for process 1
• C

  entropy remains constant in process 2
• D

  the average speed of molecules remains constant for process 3

Hence, the correct answer is options: 'A', 'B'.