38. Which measurement is closest to the actual outside diameter of a 4-inch

Answer: C

Explanation:

4 1/4 inches

The measurement closest to the actual outside diameter of a 4-inch Schedule 40 steel pipe is 4 1/4 inches. This reflects the nominal size of the pipe and the standardized dimensions used in plumbing.

A) Schedule 40 steel pipe

This option is not a measurement but rather a type of pipe classification. While it denotes a specific standard for pipes, it does not provide a numerical measurement that relates to the outside diameter of the pipe.

B) 4 inches

The nominal size of the pipe is indeed 4 inches, but this measurement refers to the internal diameter, not the actual outside diameter. Therefore, this option does not accurately represent the outside diameter.

C) 4 1/4 inches

This option accurately represents the actual outside diameter of a 4-inch Schedule 40 steel pipe, as the standard dimensions indicate that the outside diameter is approximately 4 1/4 inches. Thus, this is the correct choice.

D) 4 5/8 inches

Although this measurement is close, it exceeds the actual outside diameter of a 4-inch Schedule 40 steel pipe. This option is not correct as it does not align with the standardized dimensions.

E) 5 inches

This option is significantly larger than the actual outside diameter of a 4-inch Schedule 40 steel pipe. It does not reflect any standard measurement for this type of pipe and is therefore incorrect.

Conclusion

The correct answer is 4 1/4 inches, as it is the standardized measurement for the outside diameter of a 4-inch Schedule 40 steel pipe. All other options either misrepresent the size or refer to incorrect measurements that do not apply to the pipe in question.