Question

If ${10}^9$ electrons move out of a body to another body every second, then the time required to get a total charge of $1C$ on the other body is then

• A. $250$ years
• B. $100$ years
• C. $198$ years
• D. $150$ years

Answer 1

Answer: (C)

$198$ years

The charge given out on one second
$=1.6\times {10}^{-19}C\times {10}^9=1.6\times {10}^{-10}C$
Time requried to accumulate a charge of $1C$
$=\frac{1}{1.6\times {10}^{-10}}=6.25\times {10}^{9}s=198$ years