Question

In a Neon discharge tube $2.9\times {10}^{18}N{e}^{+}$ ions move to the right each second, while $1.2\times {10}^{18}$ electrons move to the left per sec., electron charge is $1.6\times {10}^{-19}C$. The current in the discharge tube :-

• A. 1 A towards right
• B. 0.66 A towards right
• C. 0.66 A towards left
• D. zero

Answer 1

The correct option is B 0.66 A towards right

Here the net charge particles flow per sec is $n=2.9\times {10}^{18}+1.2\times {10}^{18}=4.1\times {10}^{18}$
The current is $I=ne=4.1\times {10}^{18}\times 1.6\times {10}^{-19}=0.66A$
Current direction is opposite to the electrons direction so current flow towards right.