the p.d across the plates of a parallel plate capacitor,when space b/w them is evacuated is 9v.find the p.d?

Question

find the pottential difference across ,when a slab of relative permitivity epsilon=6 fill the space b/w the plates.

Answer 1

it depends whether the capacitor is still connected to the power source if yes the pd will remain the same if no pd will be 9/6 ie 1.5

Answer 2

Well, the charge on the plates stays the same, but the capacitance is multiplied by 6. C=Q/V, so V=9/6=1.5 volts.

Answer 3

q=cv
v=q/c
q=9
c=6
v=9/6=1.5v