Question

If current of one ampere flows through a conductor, the number of electrons flowing across the cross section of the conductor in 2 seconds is _____(Take the charge on an electron equal to 1.6 x ${10}^{-19}C$)

• A. $1.6\times {10}^{-19}$
• B. $1.25\times {10}^{19}$
• C. $6.25\times {10}^8$
• D. $3.2\times {10}^{18}$

Answer 1

Answer: (B)

$1.25\times {10}^{19}$

The current is defined as the rate of charge flowing through the circuit.

$I=\frac{Q}{t}⟹Q=It$

$I=1A$ and $t=2s$

$⟹Q=2C$

Now $Q=Ne$ where $N=$ number of electrons

$⟹N=\frac{2}{1.6\times {10}^{-19}}$

$⟹N=1.25\times {10}^{19}$

Answer-(B)