Question

A copper plate is introduced between the plates A and B of a parallel plate capacitor as shown in the figure. The copper plate is not in contact with A or B. Which one of the following statements is correct?

• A. A charge is not induced in copper plate.
• B. The copper plate divides the capacitor into two capacitors connected in parallel.
• C. The copper plate divides the capacitor into two capacitors connected in series.
• D. The effective distance between the plates of the capacitor is reduced.

Answer 1

The correct option is C The copper plate divides the capacitor into two capacitors connected in series.

Due to the polarization some positive charge induced on the copper plate and negative charge induced on A and B.
Here copper plate will divide the capacitor into two capacitor and they are in series. The equivalent structure is shown in figure.
The effective distance $d_{eff}=(d/2+d/2)=d$ between the capacitor will remain same.