+1)nR∆T If f=2⇒Q=2nR∆T⇒2×1×8.3×1.2=19.92 (No option is matching) If f=5⇒Q=3.5nR∆T ⇒3.5×1×8.3×1.2=34.86 (No option is matching) 2nd Method Q=∆U+W Q=
f
2
nR∆T+P∆V If f=2 ⇒Q=nR∆T+P∆V =1×8.3×1.2+105×25×10−3×4×10−4 =10.96 (No option is matching) If f = 5 ⇒Q=2.5nR∆T+P∆V 2.5×1×8.3×1.2+105×25×10−3×4×10−4 =25.9 (closest is 25)