Question

Calculate the drift speed of electron in a copper wire carrying a current of 1A and
cross sectional area A = 10^-6 m^2. The electron density of copper that was
found experimentally is n = 8.5x10^28 m^–3. (Take q = 1.6X10^-19 C)​

Answer 1

Answer:

Given: a copper wire of cross-sectional area 2.5×10

−7

m

2

carrying a current of 2.7A. The density of conduction electrons to be 9×10

28

m

−3

To find the average drift speed of conduction electrons

Solution:

We know that drift velocity,

V

d

=

nq×A

I

, where I=2.7A is the current, n=9×10

28

m

−3

is the charge density, q=1.6×10

−19

is charge electron and A=2.5×10

−7

m

2

is cross-sectional area

That is, V

d

=

9×10

28

×1.6×10

−19

×2.5×10

−7

2.7

⟹V

d

=

14.4×10

9

×2.5×10

−7

2.7

⟹V

d

=0.075×10

−2

⟹V

d

=7.5×10

−4

m/s

is the required averagedrift velocity of conduction electrons.

Answer 2

Answer:

The electron density of copper that was found experimentally is n = 8.5x10^28 m^–3. ( Take q = 1.6X10^-19 C).