Question

The advantages of using dielectrics are :

• A. Increases capacitance.
• B. Higher dielectric strength.
• C. Increased stability.
• D. All of these.

Answer 1

The correct option is D All of these.

Yeah! the dielectric increases capacitance by k times (k is the dielectric constant) which is good because for the same potential difference across it we can now store more energy,
$E=\frac{1}{2}C{V}^2$
As the dielectric strength increases we are able to put more charge on the capacitor plates as it would now be able to withstand a higher electric field without breaking down!
The plates of a parallel palate capacitor have equal and opposite charge and obviously they attract each other and if left to themselves will get pulled towards each other. So we need something in b/w to keep them at a small distance of d.
Dielectric does that in a capacitor thus providing it stability!