Q.

A capacitor, C1=6 μF is charged to a potential difference of V0=5 V using a 5 V battery. The battery is removed and another capacitor, C2=12 μF is inserted in place of the battery. When the switch 'S' is closed, the charge flows between the capacitors for some time until equilibrium condition is reached. What are the charges (q1 and q2) on the capacitors C1 and C2 when equilibrium condition is reached          [2025]

1 q1=15 μC, q2=30 μC  
2 q1=30 μC, q2=15 μC  
3 q1=10 μC, q2=20 μC  
4 q1=20 μC, q2=10 μC  

Ans.

(3)

Initially Finally
q1'=6×5=30 μC

6VC+12VC=30+0

18VC=30

 VC=3018=53 Volt

 q1=6×53=10 μC

and q2=12×53=20 μC