Current Electricity Charging Discharging Of Capacitors Question 113

Question: Resistance of a voltameter is $ 2,\Omega , $ it is connected in series to a battery of 10 V through a resistance of $ 3,\Omega $ . In a certain time mass deposited on cathode is 1 gm. Now the voltameter and the $ 3,\Omega $ resistance are connected in parallel with the battery. Increase in the deposited mass on cathode in the same time will be

Options:

A) 0

B) 1.5 gm

C) 2.5 gm

D) 2 gm

Show Answer

Answer:

Correct Answer: B

Solution:

Remember mass of the metal deposited on cathode depends on the current through the voltameter and not on the current supplied by the battery. Hence by using $ m=Zit, $ we can say $ \frac{m _{Parallel}}{m _{Series}}=\frac{i _{Parallel}}{i _{Series}} $

Therefore $ m _{Parallel}=\frac{5}{2}\times 1=2.5gm. $ Hence increase in mass = 2.5 ? 1 = 1.5 gm