Question

find the resistance of wire of lenth 20 cm d=2mm and resistivity of wire is is 3.2x10

Answer 1

Given :

L = 20 cm

d = 2 mm = 0.2 cm

r = 0.2 / 2 = 0.1 cm

Resistivity = 3.2 × 10 = 32

now we know that;

Resistance = Length×Resistivity/ Area

so area of the cross section= π×(r)×(r)

= 3.14 × 0.1 × 0.1

= 0.0314 square cm

now,

Resistance = 20×32/ 0.0314

= 18,823.52 ohm