Charges Q1 and Q2 are given to two plates of a parallel plate capacitor. The capacity of the capacitor is C. When the switch is closed, mark the correct statement(s). (Assume both Q1 and Q2 to be positive.)

As the switch is closed, the charge on the outer surface of the second plate becomes zero. From the concept in electrostatics that electric field inside the bulk of the material of conductor is zero, we can find the charges on various faces. So it is clear that Q1 + Q2 charge goes from the second plate to the earth. Charge on capacitor is Q1 and hence its potential is Q1/C.