Journeyman Electrician’s Exam Journeyman Electrician's Conduit Bending 3

Question 1

What is "shrinkage" in the context of conduit offsets?

Accepted Answer

The amount the straight conduit run must be shortened to account for horizontal distance lost in the offset

Answer

Shrinkage is the reduction in straight run length required because an offset section covers less horizontal distance than a straight section of equal conduit length would.

Question 2

For a 45-degree offset, the shrinkage is approximately how much per inch of offset height?

Accepted Answer

0.414 inch

Answer

A 45-degree offset has a shrinkage of approximately 0.414 inches per inch of offset height (the multiplier 1.414 minus 1.000 = 0.414).

Question 3

What is a "rolling offset" in conduit bending?

Accepted Answer

An offset that travels in two planes simultaneously, both vertically and horizontally

Answer

A rolling offset must move in two planes at once, requiring trigonometric calculations to determine the true offset distance and the correct angle for bending.

Question 4

When multiple parallel conduits must all make 90-degree bends while remaining evenly spaced, which bending technique is used?

Accepted Answer

Concentric bending

Answer

Concentric bending maintains even spacing between parallel conduits by progressively increasing the bend radius for each successive outer conduit in the group.

Question 5

For a conduit offset over an 8-inch high obstacle using 45-degree bends, what is the total shrinkage to deduct from the straight conduit run?

Accepted Answer

3.31 inches

Answer

Shrinkage = 8 x 0.414 = 3.31 inches must be subtracted from the straight conduit run to properly lay out the full run.

Journeyman Electrician’s Exam Practice Test

Journeyman Electrician’s Exam Practice Test

Journeyman Electrician’s Exam Journeyman Electrician's Conduit Bending 3