How the gravitational constant will change if a brass plate is introduced between two bodies ?

The gravitational force between two bodies is :

Two charges are placed a certain distance apart in air. If a brass plate is introduced between them, the force between them will

The force between two point charges in vacuum is 15N, if a brass plate is introduced between the two charges, then force between them will -

The gravitational force between two bodies is

Gravitational force between two bodies exist

A parallel plate air-core capacitor is connected across a source of constant potential difference. When a dielectric plate is introduced between the two plates then:

Separation between the plates of a parallel plate capacitor is d and the area of each plates is A . When a slab of material of dielectric constant k and thickness t(t lt d) is introduced between the plates. Its capacitance becomes