Question

For a metal that has an electrical conductivity of 7.1 x 10⁷ ( $\Omega$ -m)^-1, do the following:

(a) Calculate the resistance (in $\Omega$ ) of a wire 2.6 mm in diameter and 6.7 m long.

(b) Calculate the current (in A) if the potential drop across the ends of the wire is 0.060 V.

(c) Calculate the current density (in A/m^2).

(d) Compute the magnitude of the electric field (in V/m) across the ends of the wire.

Answer 1

The formulafor the resistance (r) is as follows ca Here, C is the conductance, ł is the length and a is the area. Calculate the resistance as follows: Td 4 3.15(0.0026 m) 4 -5.32x10-6 m2 6.7 m -6 2 7.1x10' ohm -m 5.32x10° m - 1.77x10 ohm

The formula for the current A) is as follows: 0.060 V 1.77 10 ohm -3.38 A Calculate the current density as follows: 3.38 amp 5.32x10 m -6.36x105 A,m-2

Calculate the magnitude of electric field as follows: 636x105 amp.m-2 7.1x107ohmm1 = 8.96x10-3 Amp. ohm.m-1 or V/m