# Why does the Pressure ratio across the compressor increases when the mass flow rate is reduced?

I am learning about Rotating stall in Axial Flow Compressors. So, when we throttle the compressor then there is Pressure Rise and later after the peak pressure rise tip stall starts to appear. But I am trying to figure out the relation between mass flow rate and pressure rise.

Mathematically, Bernoulli's Theorem is expressed $\rho \times v =$ constant.
Here, $\rho$ is density, $v$ is velocity.