Question

If 100 KWh of energy is consumed at 33V in a copper voltameter, then the mass of copper liberated will be $($ Given e.c.c. of $Cu=0.33\times {10}^{-6}$ kgC${}^{-1})$

• A. 3.3 kg
• B. 3.6 kg
• C. 1 kg
• D. 1 mg

Answer 1

Answer: (B)

3.6 kg

Given that
P = 100 KWh

e.c.e. of copper, $Z=3.3\times {10}^{-7}Kg{C}^{-1}$

Here, 100 KWh of energy is consumed at 33 V in copper voltmeter hence,

$Q=\frac{P}{V}$

$Q=\frac{100\times {10}^3\times 3600}{33}$

$Q=1.090\times {10}^7$

Now, the mass of copper liberated is

$m=ZQ$

$m=(3.3\times {10}^{-7})(1.090\times {10}^7)$

$m=3.6Kg$