A silver and a copper voltameter are connected in series with a `12.0 V` battery of negligible resistance. It is found that `0.806g` of silver is deposited in half an hour.Find (a) the mass of the copper deposited and (b) the energy supplied by the battery. `ECE` of silver `= 1.12 xx 10^(-6) kg C^(-1)` and that of copper `= 6.6 xx 10^(-7) kg C^(-1)`

Explanation

(a) F silver voltameter, the formula `m = Zit gives
`0.806 g = (1.12 xx 10^(-6) kg C^(-1)) I (30 xx 60 s)`
or, ` I = 0.4 A`.
As the two voltameters are connected in series, the same current passes through the copper voltameter. The mass of copper deposited is
`m = Zit`
`= (6.6 xx 10^(-7) kg ^ ^(-1)C) (0.4 A) (30 xx 60 s)`
`= 4.75 xx 10^(-4) kg = 0.475 g`.
This could also be obtained by using `m_1/m_2 = Z_1/Z_2` for series circuit.
(b) Energy supplied by the battery `= Vit`
`= (12 V) (0.4 A) (30 xx 60 s) = 8.64 kJ`.