The correct option is D −20 kJ
The change in internal energy for diatomic gas is given by,
ΔU=nCVΔT=nCV(TB−TA)
n→ no of mole, Here n=1
CV→ Specific heat capacity at constant volume
ΔT→ change in temperature
For a diatomic gas, CV=52R
From ideal gas equation, PV=nRT
TA=PAVAR; TB=PBVBR
⇒ΔU=1×52×R×(PBVBR−PAVAR)
ΔU=52(PBVB−PAVA)
From the given graph,
PA=5×103 Pa ; VA=4 m3
PB=2×103 Pa ; VB=6 m3
⇒ΔU=52[(2×103×6)−(5×103×4)]
⇒ΔU=−20 kJ
Hence, option (D) is correct.