Question

After the switch in the circuit above has been closed for a long time, what will the charge be on the $4.00\mu F$ capacitor and on the $6.00\mu F$ capacitor?

• A. $40\mu C$ and $60\mu C$
• B. $60\mu C$ and $60\mu C$
• C. $40\mu C$ and $40\mu C$
• D. $60\mu C$ and $40\mu C$

Answer 1

The correct option is A $40\mu C$ and $60\mu C$

When the switch S is closed for a long time, the capacitors are fully charged and they will act as open circuit. So no current will flow through the circuit. Thus as both capacitors are in parallel so potential them will be equal to 10 V.

Hence, charge on $4\mu F$ is $Q_4=C_{4}V=4\times 10=40\mu C$ and charge on $6\mu F$ is $Q_6=C_{6}V=6\times 10=60\mu C$