Question

In a region, $10^{19}\alpha$ -particles 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

Answer 1

Answer: (C)

An $\alpha$ -particle has a charge equal to 2 protons and 2 neutrons. 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
$i=10^{19}\times \left(2\times 1.6\times 10^{-19}\right)+10^{19}$
$\times \left(1.6\times 10^{-19}\right)+10^{19}\times \left(1.6\times 10^{-19}\right)=6.4A$