Question

What is the amount of charge possessed by $1 kg$ of electrons? Given that mass of an electrons is $9.1 \times 10^{-31} kg$.

• A. $6.25 \times 10^{10} C$
• B. $1.76 \times 10^{11} C$
• C. $1.76 \times 10^{10} C$
• D. $1.25 \times 10^{10} C$

Answer 1

Answer: (B)

$n=\frac{M}{m_{e}}=\frac{1 \,kg }{9.1 \times 10^{-31} kg }=1.1 \times 10^{30}$
Therefore, charge on $1 \,kg$ of electrons,
$q=n e=1.1 \times 10^{30} \times 1.6 \times 10^{-19}$
$=1.76 \times 10^{11} C$