🔍 Key Concepts

• Centrifugal pump affinity laws that relate head, flow, and power to impeller diameter and speed • How head (pressure energy) changes when you change only the impeller diameter, keeping speed constant • The difference between a quantity varying directly, with the square, or with the cube of another quantity

💭 Think About

• If you increase the impeller diameter by 10%, how would the discharge head change according to pump affinity laws? Would it increase by 10%, 21%, or 33%? • Think about which pump performance variable (flow, head, or power) is associated with a square relationship in the affinity laws. • Which of the options describes a relationship that matches standard textbook pump curves for changing impeller diameter at constant speed?

✅ Before You Answer

• Review the pump affinity laws: how head (H) relates to impeller diameter (D) when speed is constant • Confirm which variable is associated with the square of diameter and which with the cube of diameter • Make sure you focus on discharge head, not flow rate or power, when matching the relationship to the choices