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Question
A current of 1.6 mA flows through a conductor. If charge on an electron is –1.6 × 10-19 coulomb, find the number of electrons that will pass each second through the cross section of that conductor.
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Solution
Current, I = 1.6 mA = 1.6 × 10-3 A
Charge, Q = -1.6 × 10-19 coulomb
t = 1 sec
Charge flowing through the conductor in one second
I = `"Q"/"t"`
Q = I × t
Substituting the values in the formula above we get,
Q = 1.6 × 10-3 × 1
= 1.6 × 10-3
No. of electrons = `(1.6 xx10^-3)/(1.6xx10^-19)`
= `10^16`
Therefore, the number of electrons that will pass each second through the cross section of that conductor = 1016
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