Current Electricity Charging Discharging Of Capacitors Question 380

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 second. Electron charge is $ 1.6\times {{10}^{-19}}C $ . The current in the discharge tube

[MP PET 1999]

Options:

A) 1 A towards right

B) 0.66 A towards right

C) 0.66 A towards left

D) Zero

Show Answer

Answer:

Correct Answer: B

Solution:

Net current $ i={i _{+}}+{i _{-}}=\frac{({n _{+}}),({q _{+}})}{t}+\frac{({n _{-}}),({q _{-}})}{t} $

Therefore $ 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}} $

Therefore $ i=,0.66,A $