Q. In a neon discharge tube $2.9 \times 10^{18}Ne^{+}$ ions move to the right each $second$ while $1.2 \times 10^{18}$ electrons move to the left per $second.$ 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
Explanation

(b) Net current $i = i_{+} + i_{-} = \frac{(n_{+})(q_{+})}{t} + \frac{(n_{-})(q_{-})}{t}$
$\Rightarrow i = \frac{(n_{+})}{t} \times e + \frac{(n_{-})}{t} \times e$
$= 2.9 \times 10^{18} \times 1.6 \times 10^{- 19} + 1.2 \times 10^{18} \times 1.6 \times 10^{- 19}$
$\Rightarrow i = 0.66\ A$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.