A uniform copper wire of length 1 m and cross-section area 5 × 10 - 7 m 2 carries a current of 1 A . Assuming that there are 8 × 10 28 free electrons per m 3 in copper, how long will an electron take

Question

A uniform copper wire of length 1 m and cross-section area 5 × 10 - 7 m 2 carries a current of 1 A . Assuming that there are 8 × 10 28 free electrons per m 3 in copper, how long will an electron take to drift from one end of the wire to the other?

TestHub · Accepted Answer

Current in wire i = A n e v d Here, A = 5 × 10 - 7 m 2 ∴ 1 = 8 × 10 28 × 1.6 × 10 - 19 × 5 × 10 - 7 × v d o r v d = 1 8 × 10 28 × 1.6 × 10 - 19 × 5 × 10 - 7 Now, t = 1 v d = 8 × 10 28 × 1.6 × 10 - 19 × 5 × 10 - 7 = 64 × 10 2 = 6.4 × 10 3 s

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