CALCULATING THE NUMBER OF ELECTRONS

Electricity and Magnetism Level 2

The current in the wire is 8A, the number of electrons passing through a certain cross section of the wire within 40s is ? (the amount of electron charge is e=1.6×10^-19 C).

Hint :The amount of charge passing through the conductor can be calculated by physics formula : Q=It

2.0×10^21 1.6.0×1021 2.0×10^19 2.0×10^22

1 solution

Tom Engelsman
Dec 28, 2018

Knowing that $I = \frac{dq}{dt} = \frac{Nq}{t}$ , solving for $N$ gives:

$N = \frac{It}{q} = \frac{(8)(40)}{1.6 \times 10^{-19}} = \boxed {2 \times 10^{21}} electrons.$

CALCULATING THE NUMBER OF ELECTRONS

1 solution

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