Determine the current strength in the section of the circuit consisting of a constant wire 20 m long

Determine the current strength in the section of the circuit consisting of a constant wire 20 m long, with a cross section of 1.26 mm2, if the voltage at the ends of this section is 40V. Specific resistance constant 0.5 Ohm * mm2

Given: l (length of the wire that makes up the chain section) = 20 m; S (section of constantan wire) = 1.26 mm2; U (voltage at the ends of the selected section of the circuit) = 40 V.

Constants: by condition we take ρ (specific electrical resistance of constantan) = 0.5 Ohm * mm2 / m.

The formula for calculating the current in the circuit section is: I = U / R = U / (ρ * l / S).

Calculation: I = 40 / (0.5 * 20 / 1.26) = 40 * 1.26 / (0.5 * 20) = 5.04 A.

Answer: The current strength is 5.04 A.