Figure shows a cyclic process performed on one mole of an ideal gas. A total of 1000 J of heat is withdrawn from the gas in a complete cycle. Find the work done on/by the gas, in joule, during the process B→C. Given R = 8.3 J mol-1 K-1

For a cyclic process, ΔU=0⇒ Qcycle =Wcycle    ……..(1)where, Wcycle =WA→B+WB→C+WC→A …….(2)Process C→A is isochoric, hence WC→A=0Process A →B is isobaric, as its T-V graph is a straight line passing through origin.In an isobaric process, work done is         WA→B=PVB−VA=nRTB−TA⇒ WA→B=1×8.3(400−300)=830J    ........(3)WA→B is positive, so expansion of gas takes place.From equations (1), (2) and (3), we get−1000=830+WB→C+0⇒ WB→C=−1830 JNegative work done implies that compression of the gas takes place or work is done on the system/gas.