Question

A steel plate of size $6cm\times 6cm$ is to be coated by a metal on both sides with a coating thickness of 0.1 mm by electrolysis. If the density and ece of the metal are respectively $10gc{m}^{-3}$ and $0.001g{C}^{-1}$, then the strength of the current to complete the process in one hour is

• A. 1 A
• B. 0.5 A
• C. 6 A
• D. 2 A
• E. 3 A

Answer 1

The correct option is D 2 A

Since electrochemical equivalent (e.c.e.), $Z=\frac{m}{it}$

$m=\rho V$

$V=2\times 6\times 6\times 0.01c{m}^3$

Now $i=\frac{\rho V}{Zt}$

$i=\frac{10\times 2\times 36\times {10}^{-2}}{{10}^{-3}\times 60\times 60}$

$=2A$