Answer key for physics question (1)

(a) R = v /I = 120 / 0.25 = 480 Ω


(b) P = IV = (0.25)(120) = 30 w


(c) I = q / t ; q = (0.25)(15) = 3.75 C


     (3.75)(1 / 1.6 x 10^-19) = 2.34 x 10^-19  e^-