The wire with resistance R was cut into two parts and, putting them together, twisted. What is the resistance of this tourniquet now?

Given:

R is the resistance of the conductor.

It is required to determine the resistance of a structure made of two twisted conductor halves.

Let the conductor consist of two identical parts with resistance r, connected in series. Then each of this part will have a resistance equal to:

r + r = R;

2 * r = R;

r = R / 2.

According to the condition of the problem, the parts of the conductor were connected in series, that is:

1 / r + 1 / r = 1 / Rtot;

2 / r = 1 / Rtot;

Rtot = r / 2 = R / (2 * 2) = R / 4.

Answer: the resistance of the harness will be equal to R / 4