Electric Charge Physics Example 3

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Example 3

medium
A current of 2 A2 \text{ A} flows through a wire for 30 s30 \text{ s}. How many electrons pass through the wire? Use e=1.6×10−19 Ce = 1.6 \times 10^{-19} \text{ C}.

Solution

  1. 1
    Total charge: Q=It=2×30=60 CQ = It = 2 \times 30 = 60 \text{ C}.
  2. 2
    Number of electrons: n=Qe=601.6×10−19=3.75×1020n = \frac{Q}{e} = \frac{60}{1.6 \times 10^{-19}} = 3.75 \times 10^{20}

Answer

n=3.75×1020 electronsn = 3.75 \times 10^{20} \text{ electrons}
Even a modest current involves an enormous number of electrons flowing per second. Each electron carries a tiny charge, so vast numbers are needed to produce measurable currents.

About Electric Charge

A fundamental property of matter that causes it to experience a force in an electromagnetic field. Measured in coulombs (C).

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