Question

A current of $1A$is drawn by a filament of an electric bulb. The number of electrons passing through a cross-section of the filament in $16seconds$ would be roughly?

• A. ${10}^{20}$
• B. ${10}^{16}$
• C. ${10}^{23}$
• D. ${10}^{18}$

Answer 1

The correct option is A

${10}^{20}$

Explanation for the correct option A: ${10}^{20}$

Step 1: Given data

Electric current flowing through the filament, $i=1A$

Number of electrons passing through the filament, $n=?$

Time duration in which the electrons flow through the filament, $t=16s$

Step 2: Formula used

$i=\frac{n\times e}{t}$

$n=\frac{i\times t}{e}$ …………………….(a)

Where, ($e$) is the charge on the electron.

$e=1.6\times {10}^{-19}C$

Step 3: Calculation of the number of electrons flowing through the filament

Substituting the given values in equation (a), we get

$$\begin{gathered} n=\frac{1A\times 16s}{1.6\times {10}^{-19}C} \\ n=\frac{1\times 16}{16\times {10}^{-20}} \\ n={10}^{20} \end{gathered}$$

Hence, option (A) is correct.