in the tank is the controlled variable, and the inlet flow rate is the manipulated variable. Develop the transfer function relating the liquid level to the inlet flow rate, considering the tank geometry, the resistance to flow through the inlet and outlet pipes, and any relevant time constants.

$2-$ Develop a transfer function relating to simple U$-$tube manometer. When the pressure at the top of the two legs are equal, the two liquid levels are at rest at the same horizontal plane. Assume pressure difference $=P1-P2$ on the two legs