Question

A copper wire has a circular cross section with a radius of 1.50 mm. (a) If the wire carries a current of 2.60 A, find the drift speed of the electrons in the wire. (Assume the density of charge carriers (electrons) in a copper wire is n = 8.46 1028 electrons/m3.) m/s (b) All other things being equal, what happens to the drift speed in wires made of metal having a larger number of conduction electrons per atom than copper? Explain.

Answer 1

Answer:

Part a)

$v_d = 2.72 \times 10^{-5} m/s$

Part b)

it is inversely depends on the number density so on increasing the number density the drift speed will decrease

Explanation:

Part a)

As we know that the cross-sectional radius is

$r = 1.50 mm$

now we will have

$A = \pi r^2$

$A = \pi(1.50 \times 10^{-3})^2$

$A = 7.07 \times 10^{-6} m^2$

now we know that

$i = neA v_d$

so we will plug in all data

$2.60 = (8.46 \times 10^{28})(1.6 \times 10^{-19})(7.07\times 10^{-6})v_d$

$v_d = 2.72 \times 10^{-5} m/s$

Part b)

As we know that

$i = neAv_d$

now if all other things are same

$v_d = \frac{i}{neA}$

since it is inversely depends on the number density so on increasing the number density the drift speed will decrease