A wire carries a current of 2.0 A. The number of electrons crossing through its cross-section in 10 s will be
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 1.25 \times 10^{20} \)
Current is the charge crossing a section per unit time, and charge is quantised in units of \( e \), so \( q = It = ne \).
\( \displaystyle q = I\,t = 2.0 \times 10 = 20\,\mathrm{C} \)
\( \displaystyle n = \frac{q}{e} = \frac{20}{1.6\times10^{-19}} = 1.25\times10^{20} \)