Answer:
Answer:
21.2 years
Explanation:
Length, L = 2.03 x 10^2 km = 2.03 x 10^5 m
Diameter, d = 2 cm
radius, r = 1 cm = 0.01 m
Current, i = 1.03 x 10^3 A
charge density, n = 8.53 x 10^28 electrons/m^3
Let the time taken by the electrons be t.
By the use of the formula for the drift velocity
i = n e A vd
where, e be the electronic charge, A be the area of crossecion and vd be the drift velocity
1.03 x 10^3 = 8.53 x 10^28 x 1.6 x 10^-19 x 3.14 x 0.01 x 0.01 x vd
vd = 3.033 x 10^-4 m/s
time taken, t = length / drift velocity
t = 2.03 x 10^5 / (3.033 x 10^-4)
t = 6.69 x 10^5 seconds
t = 21.2 years
Thus, the time taken is 21.2 years.
Explanation: