The cycle operates irreversibly

  A system undergoes a power cycle while receiving 1500 kl by heat transfer from a thermal reservoir at a temperature of 650 K and discharging 750 kl by heat transfer to a thermal reservoir at (a) 375 K, (b) 325 K, (c) 275 K. For each case, determine whether the cycle operates irreversibly, operates reversibly, or is impossible. (Watch "Carnot Engine Example-4")