Answer:
Option B
Explanation:
n=1, r=53
T-V equation in adiabatic process is
TVr-1 = constant
T1 V1r-1 =T2 V2r-1
⇒ T2 = T1 (V1V2)r−1 = 100×(18)23
⇒ T2 =25 K
Cv=32R for monoactomic gas
∴ △U=nCv△T=n×(3R2)(T2−T1)
= 1×32×8×(25−100)
= -900 J
Therefore, Decreases in internal energy = 900 J