If the tip size is reduced and pressure is increased but flow stays the same, what happens to the friction loss?

When the tip size is reduced while the pressure is increased but the flow remains constant, the friction loss stays the same. This is because friction loss in a hose or piping system is fundamentally related to the flow rate, the internal diameter of the pipe, and the length of the pipe.

In this case, even if the tip size and pressure change, if the flow remains constant, the factors that determine friction loss do not change. Friction loss is often calculated using established formulas, such as the Hazen-Williams formula for water flow, which shows that the friction loss is directly proportional to the flow rate raised to a certain power. Since the flow rate does not change in this scenario, the friction loss is unaffected.

The other options imply a change in the friction loss due to either a direct increase or decrease, which would not be the case when flow rate is held constant. The overall system characteristics and resistance to flow remain unchanged, leading to no variation in the calculated friction loss.