Question

A TV set shoots out a beam of electrons. The beam current is 10 A. How many electrons will strike the TV screen in a minute?

• A. $16\times {10}^{19}$
• B. $16\times {10}^{-19}$
• C. $375\times {10}^{19}$
• D. $116\times {10}^{19}$

Answer 1

The correct option is C

$375\times {10}^{19}$

Given, current, $I=10A$
and time taken $t=1minute=60s$
We know, charge of an electron, $q=1.6\times {10}^{-19}C$
Let the number of electrons be $n$
We know that , $I=\frac{q}{t}$ = $\frac{ne}{t}$

$\Rightarrow 10=\frac{n\times 1.6\times {10}^{-19}}{60}$$\Rightarrow n=375\times {10}^{19}$​