Question

Two voltameters, one of copper and another of silver, are joined in parallel. When a total charge $q$ flows through the voltameters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are $Z_1$ and $Z_2$ respectively, the charge which flows through the silver voltameter is :

• A. $\frac{q}{1+\frac{z_1}{z_2}}$
• B. $\frac{q}{1+\frac{z_2}{z_1}}$
• C. $q\frac{z_1}{z_2}$
• D. $q\frac{z_2}{z_1}$

Answer 1

Answer: (B)

We know $m=zq$
$\Rightarrow z\propto \frac{1}{q}$
$\therefore \frac{z_2}{z_1}=\frac{q_1}{q_2}$
Total charge $q=q_1+q_2$
$\therefore \frac{q}{q_2}=\frac{q_1}{q_2}+1$
$\Rightarrow q_2=\frac{q}{\left(1+\frac{q_1}{q_2}\right)}$
$\therefore q_2=\frac{q}{\left(1+\frac{z_2}{z_1}\right)}$