Jitender Pal
Last Activity: 10 Years ago
Sol. r = 0.1 mm = 10^-4
R = 1 KΩ = 10^3 Ω, V = 20 V
a) No.of electrons transferred
i = V/R = 20/10^3 = 20 * 10^-3 = 2 * 10^-2 A
q = i t = 2 * 10^-2 * 1 = 2 * 10^-2 C.
No. of electron transferred = 2 * 10^-2/1.6 * 10^-19 = 2 * 10^-17/1.6 = 1.25 * 10^17.
b)Current density of wire
= i/A = 2 * 10^-2/π * 10^10^-8 = 2/3.14 * 10^+6
0.6369 * 10^+6 = 6.37 * 10^5 A/m^2.