Final answer:
The pressure rise across a pump can be calculated using the equation: Force/Area.
Step-by-step explanation:
Pressure is defined as the force divided by the area perpendicular to the force over which the force is applied. So, the correct expression to calculate the pressure rise across a pump is a) Force/Area. In this equation, force represents the force exerted by the pump and the area represents the cross-sectional area where the force is applied.