The resistance of a uniform wire will be cut into two equal sections and the two sections will be twisted together

The resistance of a uniform wire will be cut into two equal sections and the two sections will be twisted together

The resistance R = PL / s, the volume v = SL of the conductor remains unchanged in the process of lengthening or folding, so the resistance of a wire with uniform thickness will be 4 times of the original if it is lengthened to 2 times of the original. If it is cut into two equal sections and twisted together, the resistance will be 1 / 4 of the original

Cut the resistance wire with uniform thickness and 10 ohm resistance into two sections from the middle, and the resistance of each section is 10 ohm

5 ohm
A resistance wire can be seen as a series connection of two 5 ohm half resistors