Question

Charge on an electron is $1.6\times {10}^{-19}$ coulomb. Number of electrons passing through the wire per second on flowing of 1 ampere current through the wire will be

• A. $0.625\times {10}^{-19}$
• B. $1.6\times {10}^{19}$
• C. $1.6\times {10}^{-19}$
• D. $0.625\times {10}^{19}$

Answer 1

The correct option is D $0.625\times {10}^{19}$

The current is defined as rate of flow of charged particle.i.e.
i $=\frac{Q}{t}$
Hence the charge flown is,
Q $=it$
Hence Q $=1.0\times 1=1C$
The charge Q is due to electrons, therefore,
Q $=N\times e$
Here Q $=1C$
If N is number of electrons passing and e is the electronic charge of value $1.6\times {10}^{-19}$
Then,
N $=\frac{Q}{e}=\frac{1}{1.6\times {10}^{-19}}=0.625\times {10}^{19}electrons$