Question

A 2 mF capacitor is charged to a potential difference of 30 V. The battery is removed and it is connected to a series combination of two uncharged capacitors as shown in figure. The final potential difference across C₁ will be–

• A. 10 V
• B. 20 V
• C. 30 V
• D. 5 V

Answer 1

Answer: (A)

10 V

Answer 2

q_{final on the equivalent of 3mF & 6mF} = c₂

Since this charge will be on both 3mF & 6mF. Hence potential difference across c1 will be

V₁ = Ž V₁ = $\frac { 30 } { 3 }$= 10 V