Q. The current flowing in a copper voltmeter is $1.6\ A.$ The number of $Cu^{+ +}$ ions deposited at the cathode per minute are
A) $1.5 \times 10^{20}$
B) $3 \times 10^{20}$
C) $6 \times 10^{20}$
D) $1 \times 10^{19}$
Explanation
(b) Charge $Q = I\ t = 1.6\ \times 60 = 96\ C$
Let $n$ be the number of $Cu^{+ 2}\ $ions, then
$ne = Q \Rightarrow n = \frac{Q}{e} = \frac{96}{2 \times 1.6 \times 10^{- 19}} = 3 \times 10^{20}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.