For the process shown in volume-temperature (V – T ) diagram the pressure from a to b

The given V - T graph has a mathematical equation V = Vo + mT,Here m is the +Ve slope  and V0 is the y intercept which is also +Ve.Substituting the value of V in ideal gas equation P(V0 + mT) = RTP=RTV0+mT=RV0T+mSo as T increases, P increases.