An electron gun emits \( 3 \times 10^{16} \) electrons per second. What electric current does this correspond to?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 4.8\,\mathrm{mA} \)
Electric current is the charge passing per second. Each electron carries the electronic charge \( e = 1.6\times10^{-19}\,\mathrm{C} \), so for \( n \) electrons per second
\( \displaystyle I = n\,e = 3\times10^{16}\,\mathrm{s^{-1}} \times 1.6\times10^{-19}\,\mathrm{C} \)
\( \displaystyle I = 4.8\times10^{-3}\,\mathrm{A} = 4.8\,\mathrm{mA} \)