Question

A dielectric is removed from a charged parallel-platecpacitor that has been disconnected from the power supply. The result is

a decrease of the capacitance of the capacitor.

none, since the capacitor is disconnected from its power supply.

a decrease of th electrical field between the capacitor plates.

a drop of the potential differenceee between the capacitor plates.

Answer 1

With dielectric constant inserted between plates of parallel plate capacitor, electric field (E), potential difference (V), capacitance ( C ) is given by:

  

   

where:

    A = plate area
    K = dielectric constant
    d = distance between plates
    Q = charge
    = capacitance without dielectric constant

so when we remove the dielectric electric field is increased and so does the potential difference.
But the capacitance is decreased

so first option is increased