A parallel-plate capacitor has capacitance C with air between its plates. The region is filled with a dielectric slab of dielectric constant k. The capacitor remains connected to a cell of emf E while the slab is taken out. Select the correct statements.

Question

G1 Physics · Accepted Answer

With the battery connected, V=E remains fixed. Removing dielectric changes capacitance from kC to C, so ΔQ = CE(k-1) flows back through the cell and the external work is ½E²C(k-1). Hence A,B,D.