Question

the resistance of a wire of length 20 metre is 2 ohm. if the area of cross section of the wire is 2×10^-7 m squared determine its resistivity and conductivity​

Answer 1

Explanation:

we know that R=resistivity ×length / area

so resistivity = resistance × area / length

here resistance = 2 ohm

area = 2×10^-7m²

length =20m

so resistivity = 2×2×10^-7 /20 = 1/5×10^-7 = 0.2×10^-7 ohm metre

again conductivity =1/resistivity =1/0.2×10^-7 = 5×10⁷ ohm^-1

m^-1