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Question
A current of 100 mA. flows through a wire. The charge on an electron is 1.6 × 10-19 C. Find the number of electrons passing per second through the cross-section of the conductor.
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Solution
Given: I = 100mA = 100 × 10-3 A = 0.1A, e = 1.6 × 10-19 C
Let n electrons are passing per second. Charge on one electron = e
Total charge passed in one second = ne
Thus, i = ne or
n = `"i"/"e" = 0.1/(1.6 xx 10^-19) = 6.25 xx 10^17`.
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