At least inches of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, must be left at each outlet, junction, or switch point for the connection of luminaires or devices.

150mm

Explanation:

The correct answer to the given question is 150mm or 6 inch.

Atleast 150mm or 6 inches of a free conductor, measured from the point in box where it emerges from its cable sheath or raceway, must be left at each outlet, switch or junction point to lumination or connection of devices.

150mm of free conductor is required for the devices to be connected, this needs to be placed in the junctions

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.