Question

A copper wire of cross sectional area 0.01 mm2 is used to prepare a resistance of 1kohm The resistivity of copper is 1.7x10x8the length of the wire is

Answer 1

The resistance of a wire can be calculated as follows:

$$R = \rho \frac{l}{S},$$

where \rho is the resistivity of a wire, l is its length and S is a cross-sectional area.

Hence,

$$l = \frac{R S}{\rho}$$

Substituting the numerical values, we obtain:

$$l=\frac{10^3 \Omega \cdot 10^{-2} \cdot 10^{-6} m^2}{1.7 \cdot 10^{-8} \Omega \cdot m} \approx 588 \, m$$

Answer: 588 m.