What is the current in an aluminum wire connected to a 3.5V current source?
What is the current in an aluminum wire connected to a 3.5V current source? Wire length 50m, cross-sectional area 2mm2 (aluminum resistivity 0.028 Ohm * mm ^ 2 / m)
U = 3.5 V.
l = 50 m.
S = 2 mm2.
ρ = 0.028 Ohm * mm2 / m.
I -?
The strength of the current I in the conductor is directly proportional to the voltage at the ends of the conductor U and inversely proportional to the resistance of the conductor R: I = U / R – Ohm’s law.
Resistance R for a homogeneous cylindrical conductor is expressed by the formula: R = ρ * l / S, where ρ is the resistivity of the conductor, l is the length of the wire, S is the cross-sectional area of the wire.
The formula for determining the current strength I in the conductor will take the form: I = U * S / ρ * l.
I = 3.5 V * 2 mm2 / 0.028 Ohm * mm2 / m * 50 m = 5 A.
Answer: a current flows through the conductor with a force of I = 5 A.