Question

Silver and copper voltameter are connected in parallel with a battery of e.m.f. 12 V. In 30 minutes, 1 gm of silver and 1.8 gm of copper are liberated. The energy supplied by the battery is (Z_Cu = 6.6 × 10^–4gm/C and Z_Ag = 11.2 × 10^–4gm/C)

• A. 24.13 J
• B. 2.413 J
• C. 0.2413 J
• D. 2413 J

Answer 1

Answer: (A)

24.13 J

Answer 2

By using $m = zit,$ for Ag voltameter 1

= 11.2 × 10^–4 × i₁ × 30 × 60

⇒ i₁ = 0.5 amp.

For Cu voltameter 1.8 = 6.6 × 10^–4 × i₂ × 30 × 60

⇒ i₂ = 1.5 amp

Main current i = i₁ + i₂ = 1.5 + 0.5 = 2A.

So energy supplied = Vi = 12 × 2 = 24