Polytropic index n is given by
- A. $\log(p_2/p_1) / \log(v_1/v_2)$
- B. $\log(p_1/p_2) / \log(v_1/v_2)$
- C. $\log(v_1/v_2) / \log(p_2/p_1)$
- D. $\log(v_2/v_1) / \log(p_2/p_1)$
Answer: A. $\log(p_2/p_1) / \log(v_1/v_2)$
Explanation: $P_1 V_1^n = P_2 V_2^n \Rightarrow (V_1/V_2)^n = P_2/P_1 \Rightarrow n \log(V_1/V_2) = \log(P_2/P_1)$.