The length of the copper wire used in the lighting circuit is 200m. What is the resistance of such

| June 20, 2021 | education

The length of the copper wire used in the lighting circuit is 200m. What is the resistance of such a wire if its cross-sectional area is 2mm2?

To find out the resistance of the specified copper wire, consider the formula: Rp = ρm * l / S.

Const: ρm – beats. electrical resistance of copper (according to the condition of the principle ρm = 1.7 * 10-8 Ohm * m).

Data: l is the length of the specified copper wire (l = 200 m); S is the cross-sectional area (S = 2 mm2, in the SI system S = 2 * 10-6 m2, the wire can be stranded (for the lighting circuit – 3 or 2-wire), and the core can be multi-wire, but the wire cross-sectional area , in this problem, we consider common).

Let’s perform the calculation: Rp = ρm * l / S = 1.7 * 10-8 * 200 / (2 * 10-6) = 1.7 Ohm.

Answer: The resistance of the indicated copper wire should be 1.7 ohms.



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