The correct option is B 2T
Given, PT = constant
Using the ideal gas equation PV=nRT, we can say that
nRTV×T= constant
⇒T2V=k(say)
Differentiating both sides w.r.t T, we get
2TV−T2V2dVdT=0
Coefficient of volume expansion is given by
α=dVVdT
∴α=dVVdT=2TVVT2=2T
Thus, option (b) is the correct answer.