Question

A copper wire of resistivity 1.63×10^-8 ohm-m has cross section area of 10.3×10^-4 cm^2. Calculate the resustance offered by the wire of length 126m.

Answer 1

in this question we have to apply the formula to find the resistance that is:

R=RowL/A

By putting values in this formula we get the answer of this problem that is:

1.993×10^-3 ohm

Answer 2

Given : Resistivity of copper wire = 1.63×10⁻⁸ ohm/m

                     Area = 10.3×10⁻⁴cm² = 10.3×10⁻⁴×10⁻⁴m² = 10.3 × 10⁻⁸m²

                     Length = 126m

Solution: R = pl/A

               R = (1.63×10⁻⁸ × 126)/10.3 × 10⁻⁸

               R =  (1.63 * 126) / 10.3

               R =  19.93 Omh