The figure gives the electric potential V(x) along a copper wire carrying unifor
ID: 2279241 • Letter: T
Question
The figure gives the electric potential V(x) along a copper wire carrying uniform current, from a point of higher potential Vs = 9.00 ?V at x = 0 to a point of zero potential at xs = 2.60 m. The wire has a radius of 2.10 mm, and copper has a resistivity 1.69
The figure gives the electric potential V(x) along a copper wire carrying uniform current, from a point of higher potential Vs = 9.00 ?V at x = 0 to a point of zero potential at xs = 2.60 m. The wire has a radius of 2.10 mm, and copper has a resistivity 1.69 times 10-8 ? middot m. What is the current in the wire?Explanation / Answer
It is also possible to calculate the current density (amps per square metre) in the wire if its resistivity (rho) is known.
R = rho*L/A = V/I where R is the resistance of the wire, L is its length, A is its cross-sectional area, V the voltage, I the current.
I/A = V/(rho*L) = 4/rho
Taking rho for copper to be 1.68*10^-8, we get I/A = 2.36*10^8A/m^2