Question

A copper wire of 10-6 m² area of cross
section, carries a current of 2 A. If the
number of free electrons per cubic
meter in the wire is 8 x 1028, calculate
the current density and average drift
velocity of electrons.​

Answer 1

Answer:

A=10 mm

2

=10×10

−6

m

2

n=5×10

20

/m

3

Current I=

R

V

=

5

25

=5 A

Drift velocity V

d

=

Ane

I

⟹ V

d

=

10×10

−6

×5×10

20

×1.6×10

−19

5

=6.25×10

3

m/s