Question

An aluminium wire of diameter 4 mm carries a current of 2.2 A. Then the current density is

Answer 1

So here we've an aluminum wire of thickness 4mm

Thus, r=2mm and I=2.2A

Current Density,

J=I/A

A= πr²= π(2x$10^{-3}$)²

J= (2.2/π(2x$10^{-3}$)²)

 =1.75x$10^{5}$ A/m²

Answer 2

Answer:

Explanation:

Diameter=2r

r=d/2

r=4mm/2

r=2mm

r=2×10^-3

j=i/a

=2.2/3.14×4×10^-6

j=1.75×10^5Am^-2