Question

For what time period should a flow of ${10}^{19}$ electrons be maintained between two points A and B to have a constant current of $8A$ between them?

• A. 8 x 10^-19 s
• B. 5 s
• C. 1.6 x 10¹⁹ s
• D. 0.2 s

Answer 1

The correct option is D

0.2 s

Given, number of electrons, $n={10}^{19}$; Current,$I=8A$

We know that, $q=ne$, where I =current, n = number of electrons, e = charge of an electron

Also, $I=\frac{q}{t}$

Hence $t=\frac{ne}{I}=\frac{{10}^{19}\times 1.6\times {10}^{-19}}{8}=0.2s$