Complete question is;
A copper wire has a circular cross section with a radius of 1.00 mm.
(a) If the wire carries a current of 2.5 A, find the drift speed of the electrons in the wire. (Assume the density of charge carriers (electrons) in a copper wire is; n_e = 8.46 × 10^(28) electrons/m³)
Answer:
V_d = 5.88 × 10^(-5) m/s
Step-by-step explanation:
We are given;
Radius; r = 1 mm = 0.001 m
Current; I = 2.5 A
Number of electrons per m³; n_e = 8.46 × 10^(28) electrons/m³
Now, formula for drift velocity is;
V_d = I/(A × n_e × q)
Where;
I is current
A is Area = πr² = π × 0.001²
A = 0.001²π
q is electron charge = 1.6 × 10^(-19) C
Thus;
V_d = 2.5/(0.001²π × 8.46 × 10^(28) × 1.6 × 10^(-19))
V_d = 2.5/42524.59815899144
V_d = 5.88 × 10^(-5) m/s