Determine the resistance of the resistor, the winding of which is made of nichrome wire with a diameter of 0.1 mm

Determine the resistance of the resistor, the winding of which is made of nichrome wire with a diameter of 0.1 mm, wound in one row turn to turn on a ceramic frame 10 mm long and 4 mm in diameter. How will the resistance change with double-row winding?

We determine the number of turns, for this we divide the length of the frame by the diameter of the wire:

n = 10: 0.1 = 100.

The length of the wire in one turn l will be:

l = π * d = 0.0126 m.

Then the total length is:

L = n * l = 1.26 m

Sectional area S:

S = π * d ^ 2/4 = 0.79 * 10 ^ (- 8) m ^ 2.

The resistance of the resistor is determined by the formula:

R = ρ * l / S, where ρ is the resistivity, l is the length, S is the cross-section of the conductor.

R = 1.15 * 10 ^ (- 6) * 1.26 / 0.79 * 10 ^ (- 8) = 180 ohms.

Answer: the required resistor value is 180 ohms.