Under which condition will the flow rate of a liquid through an orifice be the greatest?

The flow rate of a liquid through an orifice is primarily determined by the pressure differential between the liquid and the environment acting upon the orifice. The greater this pressure difference, the higher the flow rate will be.

In the scenario described, option C specifies an unmetered pressure of 17 psi and a metered pressure of 5 psi. The pressure differential, which directly influences the flow rate, can be calculated as the difference between the unmetered pressure and the metered pressure. In this case, the calculation yields a differential of 12 psi (17 psi - 5 psi).

When we consider the other options, they do not provide a greater pressure differential than that in option C. For instance, option A presents a lower unmetered pressure that leads to a lower overall pressure differential. Similarly, option B’s combination of pressures results in a lower differential because the atmospheric pressure does not factor into significantly increasing the flow through the orifice. Option D offers the highest unmetered pressure, but without a relevant metered pressure to contrast it against, the impact on the flow does not reach the optimal level seen in option C.

Thus, the combination in option C achieves the highest pressure differential, making it the condition under which