Question

When a copper voltameter is connected with a battery of emf 12 volts, 2 gms of copper is deposited in 30 minutes. If the same voltameter is connected across a 6 volt battery, then the mass of copper deposited in 45 minutes would be

• A. 1 gm
• B. 1.5 gm
• C. 2 gm
• D. 2.5 gm

Answer 1

Answer: (B)

1.5 gm

Answer 2

By using $m = zit = \frac{zVt}{R}$ ⇒ $\frac{m_{1}}{m_{2}} = \frac{V_{1}t_{1}}{V_{2}t_{2}} \Rightarrow \frac{2}{m_{2}} = \frac{12 \times 30}{6 \times 45} \Rightarrow m_{2} = 1.5gm$