If a 7-turn coil is used at 1000 A to inspect a round solid part measuring 381 mm long and 64 mm in diameter, what is the length-to-diameter ratio?

To determine the length-to-diameter ratio of the round solid part, you need to calculate the ratio of the length of the part to its diameter.

The length of the part is given as 381 mm, and the diameter is given as 64 mm. The length-to-diameter ratio is calculated using the formula:

[ \text{Length-to-Diameter Ratio} = \frac{\text{Length}}{\text{Diameter}} ]

Substituting the values:

[ \text{Length-to-Diameter Ratio} = \frac{381 \text{ mm}}{64 \text{ mm}} ]

This calculation yields:

[ \text{Length-to-Diameter Ratio} = 5.953125 ]

When rounded, this value approximates to 6.0. Thus, the correct answer is 6.0. This ratio is important because it helps define the characteristics of the part being tested, which can influence the magnetic particle testing process. The ratio indicates whether the geometry of the part is more cylindrical, which could affect how magnetic flux is distributed and how effective the inspection methods will be.