Q. In a region $10^{19}\ \alpha -$particales and $10^{19}$ protons move to the left, while $10^{19}$ electrons move to the right per second. The current is
A) 3.2 A towards left
B) 3.2 A towards right
C) 6.4 A towards left
D) 6.4 A towards right
Explanation
(c) An $\alpha -$particle has a charge equal to 2 protons. Motion of $\alpha$ particle to the left, motion of proton towards left and motion of electrons towards right, all will produce conventional current towards left. The total current will be
$i = 10^{19} \times (2 \times 1.6 \times 10^{- 19})$
$+ 10^{19} \times \left( 1.6 \times 10^{- 19} \right) + 10^{19} \times (1.6 \times 10^{- 19})$
$= 6.4\ A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.