Question

Three large plates are arranged as shown. How much charge will flow through the key k if is closed?

• A. $\frac{5Q}{6}$
• B. $\frac{4Q}{3}$
• C. $\frac{3Q}{2}$
• D. None

Answer 1

The correct option is A $\frac{5Q}{6}$

$q_1+q_2=2q$

$V_{AB}{V}_{AC}=\frac{Q_1}{C_1}=\frac{Q_2}{C_2}$

$\frac{Q_1}{C_1}=\frac{Q_2}{C_2}=2,q_1=2q_2$

$Q_1=\frac{4Q}{3},Q_2=\frac{2Q}{3}$

charge flow through

$\frac{-Q}{2}-(-q_1)=\frac{-Q}{2}+\frac{4Q}{3}$

$\frac{5Q}{6}$