Question

Electrical resistivities of some some substances at 20*C (degree) are given below

Answer 1

Explanation:

Material Resistivity ρ (ohm m) Conductivity σ x 107 /Ωm

Copper 1.68 5.95

Copper, annealed 1.72 5.81

Aluminum 2.65 3.77

Tungsten 5.6 1.79

Answer 2

Explanation:

(a) Silver having a lower resistivity is a better conductor than Copper.

(b) Since nichrome has highest resistivity, it is best preferred and suitable for an electrical heating device.