ANS:A - dependent on Reynolds number.

The equivalent length of a pipe fitting is generally considered to be independent of Reynolds number. Here's an explanation:

• Equivalent Length of Pipe Fittings: The equivalent length of a pipe fitting is a way to quantify the additional frictional losses caused by the fitting. It is expressed as the length of straight pipe that would cause the same pressure drop as the fitting. This equivalent length is typically determined from experimental data and depends on the type and geometry of the fitting.
• Independence from Reynolds Number: While the actual pressure drop across a fitting does depend on the Reynolds number (since friction factors vary with flow regime), the equivalent length itself is usually treated as a constant for a given fitting type in engineering practice. This simplifies calculations, allowing engineers to estimate pressure drops without repeatedly recalculating for different flow conditions.