Resistivity of a graphite rod = 400 Ohm * mm2 / m. What value of the current will pass through the rod if a voltage

| February 27, 2021 | education

Resistivity of a graphite rod = 400 Ohm * mm2 / m. What value of the current will pass through the rod if a voltage U = 6 V is applied to it. The length of the rod is 20 cm, the radius is 1 mm.

To determine the value of the current passed through the taken graphite rod, we use the formula: I = U / R = U / (ρ * l / S) = U * S / (ρ * l) = U * Π * R ^ 2 / (ρ * l).

Variables and constants: U – applied voltage (U = 6 V); R is the radius of the rod (R = 1 mm); ρ is the specific electrical resistance of graphite (according to the condition ρ = 400 Ohm * mm2 / m); l is the length of the taken rod (l = 20 cm = 0.2 m).

Let’s perform the calculation: I = U * Π * R ^ 2 / (ρ * l) = 6 * 3.14 * 1 ^ 2 / (400 * 0.2) = 0.2355 A.

Answer: A current of 0.2355 A will flow through the taken graphite rod.



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