Answer:
t = 141.55 years
Explanation:
As we know that the radius of the wire is
r = 2.00 cm
so crossectional area of the wire is given as
[tex]A = \pi r^2[/tex]
[tex]A = \pi(0.02)^2[/tex]
[tex]A = 1.26 \times 10^{-3} m^2[/tex]
now we know the free charge density of wire as
[tex]n = 8.50 \times 10^{28}[/tex]
so drift speed of the charge in wire is given as
[tex]v_d = \frac{i}{neA}[/tex]
[tex]v_d = \frac{1190}{(8.50 \times 10^{28})(1.6 \times 10^{-19})(1.26\times 10^{-3})}[/tex]
[tex]v_d = 6.96 \times 10^{-5} m/s[/tex]
now the time taken to cover whole length of wire is given as
[tex]t = \frac{L}{v_d}[/tex]
[tex]t = \frac{310 \times 10^3}{6.96 \times 10^{-5}}[/tex]
[tex]t = 4.46 \times 10^9 s[/tex]
[tex]t = 141.55 years[/tex]
