Question

Two large plates are given the charges as shown in figure. Now, left plate is earthed. Find amount of charge that will flow from plate to earth in $\mu C$ .

• A. 7.00
• B. 7
• C. 7.0

Answer 1

Answer: (A), (B), (C)

New charge distribution on the plate system is


When the system of parallel plates is earthed, the final charges on the outermost plates must become zero.

Since, the right plate is isolated, so the total charge of $2\mu C$ will shift onto the inner side.

Now, due to induction, the inner side of first plate must have $-2\mu C$.

The charge flown through the switch $=Q_i-Q_f$ from the first plate

The charge flown $=5-(-2)=7\mu C$