Question

A copper wire of area of cross section 4.0mm is Am long and carries a current of 10A. Free electron density in the copper is 8.0x1025 m-3. Estimate the time required by an electron to travel the length of the wire.

Answer 1

Answer:

Vd = I / neA

[where, Vd = drift velocity

I = Current

n = electron density

e = charge of electron

A = cross sectional area]

Vd = 10 / 8.0×10^25×1.6×10^-19×4×10^-6

time required to travel A m long distance = A/Vd