Question

A TV set picture tube shoots out $6.25\times {10}^{16}$ electrons in one second, then find the current flowing in the TV.
(Charge of an electron is $e=1.6\times {10}^{-19}C)$

• A. 10 mA
• B. 20 mA
• C. 30 mA
• D. 40 mA

Answer 1

The correct option is A

10 mA

Given: Number of electrons $=6.25\times {10}^{16}$
Time, $t=1s$
Charge on one electron, $e=1.6\times {10}^{-19}C$

Now, $I=\frac{q}{t}$
and $q=n\times e$ (q is the charge and n is the number of electrons)
$\Rightarrow$ $Current,I=\frac{n\times e}{t}$

$\Rightarrow I=\frac{6.25\times {10}^{16}\times 1.6\times {10}^{-19}}{1}$$=10mA$